Electronic Journal of Plant Breeding ISSN 0975-928X NAAS Rating (2024): 5.60 Electronic Journal of Plant Breeding (EJPB) is an official online publication of Indian Society of Plant Breeders (ISPB) initiated in 2009. The main aim of this journal is to promote the general advancement of plant breeding and to create a forum to bring together and facilitate the exchange of information amongst plant breeders involved in the genetic improvement of agricultural, horticultural crops and forest trees. This journal is published as a quarterly with four issues (March, June, September and December) per year. Articles in "Electronic Journal of Plant Breeding" are Open Access articles published under the Creative Commons CC BY-NC License — Creative Commons Attribution Non-Commercial 4.0 International License . This license permits use, distribution and reproduction in any medium for non-commercial purposes only, provided the original work and source is properly cited.
Genetic variability, heritability and genetic advance studies in Carrot (Daucus carota var. sativa L.)
A study was carried out in mungbean Vigna radiata (L.) Wilczek) with eight ‘lines’ and four ‘testers’ crossed in a Line x Tester Genetic variability, heritability and genetic advance were estimated for marketable and its component yield traits in 48 lines of carrot (Daucus carota var. sativa L.). The study showed high ranges for total yield (3.15 -7.56 kg/plot), marketable yield (2.60 – 6.85 kg/plot), root length (19.57 cm – 24.92 cm) and root weight (101.33 g –182.00g). The highest estimates of PCV and GCV were for marketable yield (PCV = 39.91, GCV = 37.21) followed by total yield (PCV = 34.35, GCV = 33.06) and root weight (PCV = 23.19, GCV = 21.72) and low for juice yield (PCV = 4.20, GCV = 3.93) followed by dry matter (PCV = 6.61, GCV = 5.25) and root girth (PCV = 9.40. GCV = 1.09). Narrow differences between PCV and GCV, gave evidence to the lines that the variability existing in them was mainly due to their genetic makeup. High heritability was noticed for plant weight (96.30%) followed by total yield (92.60%), root weight (87.70%) and juice yield (87.70%). Root girth, root to shoot ratio and core girth showed low heritability estimates. High heritability in broad sense indicated that large proportion of phenotypic variance was attributable to the genotypic variance and less influenced by the environment. High genetic advance was observed for marketable yield (71.43) followed by total yield (65.58) and plant weight (45.71) whereas it was low for root girth (0.34), root to top ratio (0.53) and core girth (2.04) which indicates that these traits are likely to respond better to selection.
Carrot, Genetic variability, Heritability, Genetic advance
Genetic analysis of biparental mating and selfing in segregating populations of Bhendi [Abelmoschus esculentus (L.) Moench]
Three populations of the bhendi viz, BIP, SC , and DC population were developed in 2008 and these populations were evaluated in 2009 to study the extent of genetic variability, heritability and genetic advance for twelve characters in bhendi. Considerable variation was observed in BIP compared to SC F2 and DC F2 populations for most of the characters, which was confirmed by high mean and wider range of variation as evidenced by high PCV and GCV values for number of branches per plant, number of fruits per plant, average fruit weight (g), fruit yield per plant (g). It is revealed that intermating in early segregating generations of different individuals lead to release of additional variability, since biparental mating among the segregates in the F2 of a cross may provide more opportunity for the recombination to occur, break the linkage blocks and mop up desirable genes.
Variability studies for yield and its contributing traits in okra
Twelve okra genotypes were crossed in diallel fashion excluding reciprocals to generate 66 one-way hybrids. All the F1’s along with their parents were grown at Vegetable Research Farm of the Department of Vegetable Crops, Punjab Agricultural University, Ludhiana, Punjab during the rainy season of 2004-05. High genotypic and phenotypic coefficients of variation were noticed for number of primary branches per plant indicating maximum variability among the different genotypes. High estimates of heritability coupled with high genetic advance obtained for number of branches per plant, total yield per plant and marketable yield per plant indicating presence of additive gene effects which indicated the effectiveness of selection for these traits. Presence of high heritability coupled with low genetic advance for days to fruit picking, average fruit weight, plant height, internodal length, number of fruits per plant, fruit diameter and average fruit length revealed that straight selection has limited scope for further improving these traits.
Genetic Advance, Heritability, Variability
Heterosis and inbreeding depression for yield and yield components in safflower (Carthamus tinctorius L.)
The results of the experiment on the magnitude of heterosis and inbreeding depression in 38 genotypes (15 F1s, their 15 F2s and 8 parents) for yield and its attributes revealed highly significant variations for all the genotypes and for all the characters studied. Two hybrids for earliness and four hybrids for short stature exhibited significant negative standard heterosis, while four hybrids for number of capitula per plant, seven hybrids for number of seeds per capitulum, five hybrids for test weight and three hybrids for seed yield exhibited significant positive standard heterosis. There was positive inbreeding depression in F2 generation for all the characters in majority of the hybrids. There was non significant heterosis and inbreeding depression for oil content in F1 and F2 generations respectively.
Safflower, heterosis, inbreeding depression
Genetic analysis of yield and its component traits in drought tolerant genotypes of pigeonpea (Cajanus cajan L. Millspaugh)
In the present investigation, sufficient variability was observed in the drought tolerant pigeonpea genotypes for the traits under study. Most of the yield contributing characters showed significant positive correlation whereas, number of primary branches per plant showed significant negative correlation with seed yield. Days to maturity had maximum direct effect on seed yield followed by number of pods per plant and plant height and number of secondary branches which had negative direct effect on seed yield. Number of secondary branches per plant, number of pods per plant and days to maturity were identified as important yield components and hence, selection should be focused on these traits to improve yield in drought tolerant genotypes of pigeonpea.
Pigeonpea, variability, correlation, path analysis
Study on genetic variability and traits interrelationship among released soybean varieties of India [Glycine max (L.) Merrill]
Information on the economic characters was derived from ninety-two varieties of soybean. Analysis of variance was carried out for the data recorded on plant height, nodes plant-1, branches plant-1, 100-seed weight, days to 50 % flowering, days to maturity, grain yield, oil and protein content. Results revealed highly significant differences among varieties for all the characters. High heritability was recorded for days to maturity, days to 50 % flowering, plant height, nodes, oil and protein content, indicating the additive mode of gene action. Correlation coefficient of yield was significantly negative with days to flowering and maturity. Seed weight was negatively correlated with days to flowering, maturity, plant height, nodes but positively with oil content. Protein content, however, was positively correlated with number of branches and days to 50% flowering but negative with oil content.
Soybean, yield, oil, protein, correlation, genetic variability, heritability
Genetic studies in mungbean (Vigna radiata (L). Wilczek)
A study was carried out in mungbean Vigna radiata (L.) Wilczek) with eight ‘lines’ and four ‘testers’ crossed in a Line x Tester design to estimate mean, range, genotypic and phenotypic coefficients of variation, heritability and genetic advance for 13 trait viz., days to 50 % flowering, days to maturity, plant height, number of branches per plant, number of clusters per plant, number of pods per cluster, number of pods per plant, pod length, number of seeds per pod, 100 seed weight, harvest index, protein content and single plant yield. High heritability coupled with high genetic advance as per cent of mean were observed for plant height, number of branches per plant, number of clusters per plant, number of pods per cluster, number of pods per plant, 100 seed weight, harvest index and single plant yield confirming the additive gene action.
Heritability, Mungbean, Genetic advance, Yield.
Yield component analysis and recombinative heterosis of complex characters in QPM maize
Component analysis is the analysis of variation of complex character based on the variation of its components. For assessing the variation, components should be arranged in ontogenetical order. This allows determination of the mutually independent contributions of the components to the variation of complex character. Component analysis provides the necessary data for the exploitation of recombinative heterosis in plant breeding. Recombinative heterosis is the phenomenon where in, the progeny value of a complex character exceeds the mid parental value as a result of the multiplicative relationship between the complex character and its component traits. It is suggested that this form of heterosis may be an important cause of specific combining ability. As such, it may be involved in the heterosis of complex characters in F1 hybrids and in the hybrid- vigor encountered in interspecific hybrid populations. It is demonstrated how recombinative heterosis may be explained by a quantitative genetical model involving additive inheritance of the component traits. Current study was focused to predict progeny performance for the complex character from parental data for the component traits. This requires regression of individual components on the preceding primary characters. The contribution of the coefficient for yield component C3 (single seed weight) to variance of log yield was maximum in the parents CML 189, UMI 814, CML 145, UMI 524, CML 141 followed by the coefficient C2 (number of kernels per row) which was maximum in the parents UMI 427 and UMI 814. In the present investigation, 35 hybrid combinations were tested for progeny prediction value. Application of this procedure revealed that among the 35 crosses, five crosses exceeded the predicted mid parental value. The predicted values can serve as a basis for the selection of promising combinations. The crosses that exhibited higher values for grain yield per plant was predicted in the combination of CML 142 x UMI 426, CML 143 x UMI 427, CML144 x UMI 189, CML 144 x UMI 426 and CML 147 x UMI 426.
Maize, QPM, component analysis, progeny prediction
Correlation coefficient and path analysis study among grain quality components in rice (Oryza sativa L.)
Correlation coefficient and path analysis study among grain quality components in rice were studied in thirty crosses. Crosses were attempted in such a way that each line was pollinated by all pollen parents in line x tester pattern. The experimental material consisted of 5 lines viz., B6441-F-MR-6-0-0, G 9502, F7 10, BR 240, VL 16 and 6 testers viz., IR 64, Abhaya, MTU 1010, IRBL 10, IRBL 22 and LTH. In correlation studies, the following characters were found to be of importance in selection viz., hulling percentage (HP), paddy length (Pad L), head rice recovery (HRR), milling percentage (MP), brown rice length (BRL) and it also exhibited a positive interrelation among themselves. Selection based on hulling percentage (HP) is suitable, since it brings simultaneous improvement in all other quality parameter traits. Path analysis of head rice recovery (HRR) showed that brown rice length (BRL), milling percentage (MP), hulling percentage (HP) and water uptake (WU) were most important contributing characters towards the head rice recovery (HRR) based on their high positive direct effects.
Correlation coefficient, path analysis and grain quality.
Heterosis studies for yield and physiological traits in rice hybrids under shallow low land condition
Heterosis and heterobeltiosis were estimated for grain yield, its attributes and physiological traits in 33 cross combinations between rice cultivars (improved and landraces) and three male sterile parents (one wild abortive and two indigenous) generated through Line x Tester mating design, with the aim to develop physiologically efficient heterotic hybrid for this ecosystem. In general, the hybrids performed significantly better than the respective parents. Among the 33 hybrids, six hybrids viz., IR 58025A/OR 1898-18RAU 729-12-44, IR58025A/R 304-34, CRMS 31A/RPHR 203-3, CRMS 31A/IR 68830-NDR-1-1, CRMS32A/RPHR-203-3 and IR 58025A/CHINIKAPOOR, had significant heterosis for yield, flag leaf angle, IInd leaf angle, IIIrd leaf angle and flag leaf area.
Heterosis, Yield, Flag Leaf Area, Leaf Angle, Rice
TMV (Sv) 7 – A high yielding cosmopolitan sesame variety
The sesame culture TVS 0039 is a hybrid derivative of Si 250 x ES 22. It is an high yielding sesame variety with brown colour seed. It matures in 85- 90 days. TVS 0039 has recorded a mean yield of 737 kg/ha which is 12.8, 26.9 and 14.0 % superior to TMV 3, VRI (Sv) 1 and VRI(Sv 2), respectively under rainfed condition. During summer season, the culture registered an average yield of 781 kg/ha which is 25.6, 20.5, 34.3 and 27.8 % increase over VRI (Sv) 1, VRI (Sv 2), TMV 4 and TMV 6 respectively. The seeds are brown coloured with an oil content of 51.0 per cent. The culture is also tolerant to root rot disease.
Screening of Plantago species for physiological parameters in relation to seed yield
Isabgol is a major export oriented medicinal crop of India. The genetic variability available in this crop is limited owing to the narrow gene pool existing in our country. The physiological and growth characteristics of selected 7 species of Plantago were studied at DMAPR, Boriavi to investigate the relationship with the seed yield. Among the species studied, the lowest SLA (specific leaf area) of 0.15 cm2 g-1 was noticed in P. lanceolate. SLW (specific leaf weight) was recorded the lowest in P. coronopus (4.82 g cm-2) which was at par with P. indica. LAI also varied significantly among the species studied with the lowest being in P. arenaria (2.16) and P. serraria had the highest LAI (3. 87) among the species studied. P. ovata produced the highest biomass (21.49 g plant-1), while P. psyllium had comparable DM, however produced low seed yield (1.09 g plant-1) with HI of 0.061. P. lanceolate and P. ovata showed higher thousand seed weight among the species. P. indica (29.99 µmol CO2 m-2s-1) had the highest net photosynthetic rate among the species. Pn values for all the studied species were negatively correlated with their mean area of individual leaf (R2 0.366) and also with mean dry weight of leaves (R2 0.366). However, total biomass of plant was positively correlated with seed yield (R2 0.366). Thousand seed weight of studied species were significantly and positively correlated with the seed yield per plant (R20.771). In conclusion, leaf characteristics like high SLA, Pn , gs and TSW will positively contribute to the seed yield. These characters may be considered in the breeding programmes for the yield improvement of isabgol.
Isabgol, Plantago species, physiological parameters, seed yield.
Heterosis for green fruit yield and its components in chilli (Capsicum annuum var. longicum (D.G) Sendt) over environments
Heterosis for green fruits and related characters in chilli was studied in line × tester fashion involving five GMS lines and 10 testers. The hybrids differed significantly for all the characters, as evident from their highly significant mean square values. Mean squares due to hybrids × environments were significant for all the characters except average fruit weight, which indicated more sensitivity of hybrids to environments. The hybrids ACMS 8 ×IPS -2005 -15, ACMS 5 × IPS -2005 -15, ACMS 6 × ACS -2004 -03, ACMS 4 × IPS -2005 -15, ACMS 6 × IPS -2005 -15 and ACMS 8 x ACS -2004 -03 exhibited higher magnitude of heterobeltiosis and standard heterosis for green fruit yield per plant and number of fruits per plant. In general the hybrids, which depicted higher magnitude of heterotic effects also exerted greater amount of heterotic effects for various growth attributes and yield related traits; therefore, heterotic effects for green fruit yield could be because of direct and indirect effects of various yield contributing characters. Hence, to obtain maximum advantage of heterotic effects for green fruit yield, desired level of heterosis of each component character should be determined to identify superior hybrids in respect to yield, yield contributing characters and quality parameters. A cross ACMS 8×IPS -2005 -15 was consistent across the environments and so, it can be used for commercial exploitation after its critical evaluation.
Chilli, heterobeltiosis, standard heterosis, over environments
Quantitative inheritance for fruit traits in inter varietal crosses of okra (Abelmoschus esculentus L. Moench)
Gene effects for important fruit traits of four inter-varietal crosses of okra were estimated by partitioning the means and variances of means of six basic generations from each cross into their genetic components to assess the gene action governing the inheritance of fruit yield and earliness related traits in spring and rainy season. The additive, dominance and digenic non-allelic gene interactions were observed to govern most of the fruit traits. The non-additive gene effects were more pronounced than additive ones for most of the traits in both the environments. The evidence of duplicate type of epistasis has been obtained for all the characters in different crosses in both the seasons. Thus for developing high yielding okra cultivars, recurrent selection in biparental progenies would help in exploiting the duplicate type of non-allelic interactions and allow recombination and concentration of genes having cumulative effects in population.
okra, gene effects, fruit traits, epistasis, scales, recurrent selection
Studies on Heterosis in Okra (Abelmoschus esculentus (L.) Moench)
In the present investigation, a study was undertaken at the Department of Agricultural Botany, Annamalai University during the year 2006 – 2008 to identify potential parents and superior cross combinations for yield improvement in Okra. Six bhendi genotypes viz., Girija Vikas, MDU 1, Hissar Unnath, Arka Abhay and EC 305623 were crossed in full diallel fashion (including the reciprocals). The eight characters observed included days to 50 per cent flowering, plant height, number of branches per plant, number of fruits per plant, fruit length, fruit girth, individual fruit weight, fruit yield per plant. The results revealed that the standard heterosis for fruit yield per plant was maximum in the hybrid MDU 1 x Hissar Unnath, with a value of 65.23 per cent. This hybrid recorded high standard heterosis for all the characters except number of branches per plant and individual fruit weight.
Nature and magnitude of genetic variability and diversity studies in okra (Abelmoschus esculentus L. Moench)
In the present investigation, an attempt has been made to evaluate the genetic variability of yield contributing characters, and the genetic diversity in forty-four genotypes of okra collected from the IIHR, Bangalore, India. Analysis of variance indicated significant differences among the genotypes for different morphological characters. High GCV and PCV were observed for plant height, inter-nodal length, first flowering node, first fruit producing node, height of first flowering node, average fruit weight and number of seeds per fruit. On the basis of D2 analysis, the 44 genotypes were grouped into twelve clusters. The cluster III was the largest with eight genotypes followed by cluster I and VIII with seven, cluster II with five, cluster XII with three while, clusters IV, V, VI, IX, X and XI included only two genotype in each. The intra-cluster distance was maximum in cluster XII (28.14), while inter-cluster distance was maximum between cluster VI and VIII (35.57) followed by I and IX (35.31), thus being a good source for attempting hybridization. Among the 44 genotypes, IIHR-238, IIHR-241 showed maximum number of fruits per plant and total yield per plant (g). The characters namely days to 50% flowering (35.62%), 100 seed weight (28.44%), number of seeds per fruit (17.23%) and average fruit weight (8.14%) directly contributed towards maximum divergence and, therefore, selection of divergent parents based on these characters is recommended for getting good hybrids or segregants in okra.
Okra, genetic variability, heritability, genetic divergence, D2 statistics.
Genetic diversity analysis of groundnut genotypes using SSR markers
Groundnut (Arachis hypogaea L.), an important oilseed crop is a rich source of oil and protein. Molecular marker technologies are the effective tools and they are used for the assessment of genetic variability because they are not influenced by the environment. Among the molecular markers, Simple Sequence Repeat (SSR) has proved to be the most powerful tool for variety identification in groundnut and has much potential in genetic and breeding studies. Among the 17 SSR primer pairs used for assessing the genetic diversity, 6 primer pairs (24.0 per cent) were polymorphic. The genotype TMV 2 was susceptible to rust and late leaf spot diseases and it was separately clustered in the dendrogram and among the eleven foliar disease resistant genotypes, the genotypes viz., COG 0423, COG 0436 and COG 0432 were distantly clustered from TMV 2. Hence, by using the genotypes viz., TMV 2, COG 0423, COG 0436 and COG 0432, three combinations viz., TMV 2 x COG 0423, TMV 2 x COG 0436 and TMV 2 x C0G 0432 could be made for further studies.
Groundnut, SSR markers, DNA polymorphism, genetic diversity
Gene effects of pod yield and its components in three crosses of groundnut (Arachis hypogaea L.)
Groundnut, (Arachis hypogaea L.) is a major source of vegetable oil and protein and also a major source of fodder crop. Genetic systems that control the expression of quantitative traits facilitate the choice of the most efficient breeding and selection procedure. Generation mean analysis is commonly used in studies of inheritance of quantitative traits. Four groundnut genotypes which consist of three late leaf spot and rust resistant genotypes viz., COG 0437, COG 0438 and ICGV 97150 and one susceptible genotype TMV 2 were used in the present study. The cross TMV 2 x ICGV 97150 had additive gene action for most of the traits viz., plant height, number of pods per plant, pod yield per plant, kernel yield per plant, hundred kernel weight and shelling percentage. Hence, early generation selection could be practiced in TMV 2 x ICGV 97150. However due to the presence of epistasis, especially for rust and LLS incidence in other two crosses viz., TMV 2 x COG 0437 and TMV 2 x COG 0438, selection should be postponed to later generations.
Groundnut, generation mean analysis, additive and dominance gene effects, epistasis.
Induced variability in quantitative characters of groundnut (Arachis hypogaea L.)
Groundnut genotype AK-280 was treated with EMS 40 mM, 60 mM, gamma rays 30 kR, 40 kR, 50 kR and combination treatment of EMS 20 mM + gamma rays 20 kR. The observations on various quantitative characters were recorded in M2 generation. The flowering and maturity period was not much affected. For the character height of main axis genotype showed differential response to different treatments of mutagens. Significantly reduced height was observed in 40 kR gamma rays (7.57 cm) as compared to control. Lower doses of EMS (40 mM) and combined treatment of EMS 20 mM + gamma rays 20 kR proved effective in increasing the number of primary branches. Significant increase in number of secondary branches was observed in various treatments. Significant reduction in number of hanging pegs per plant was observed in 40 kR treatment. Number of matured pods per plant were found decreased in all the treatments except 40 mM EMS treatment. Pod yield per plant and kernel yield per plant were found increased in combined treatment of EMS 20 mM + gamma rays 20 kR. Hundred pod weight and hundred kernel weight was found increased in combined treatments and in lower dose of gamma rays (30 kR). Combined treatments and lower doses of mutagens were found effective in increasing sound mature kernel per cent. Shelling per cent and oil content were found increased in all the treatments. In the present investigation the combined treatment of EMS 20 mM + gamma rays 20 kR and gamma rays 40 kR alone were found more effective for inducing wide range of mutation in groundnut.
Mutagenesis, EMS, gamma rays, groundnut, pod yield, kernel yield, shelling percentage, 100 seed weight
Studies on general and specific combining ability in sesame (Sesamum indicum L.)
A Line × Tester analysis in sesame (Sesamum indicum L.) was carried out with seven lines and four testers to estimate the combining ability effects, nature of gene action and heterosis for eight characters viz., days to 50 per cent flowering, plant height, number of branches per plant, number of capsules per plant, capsule length, number of seeds per capsule, 1000 seed weight and seed yield per plant. Based on the general combining ability effects, IVTS 7 among lines and TMV 6 among testers were found to be good general combiners for seed yield per plant. The cross combination IVTS 7 X TMV 6 exhibited the maximum positive and significant sca for seed yield per plant and hence recommended for heterosis breeding, whereas the hybrid IVTS-13 × TMV 6 exhibited high test weight and hence it is recommended for breeding bold seeded type. Similarly the hybrid IVTS 8 × TMV 3 recorded desirable sca for earliness.
General combining ability, specific combining ability, sesame
Rapid, cost-effective screening of flax genotypes to identify desirable fatty acid compositions
Seeds of oil flax (Linum usitatissimum) are rich in polyunsaturated fatty acids and their composition is one of the major criteria for flax selection. Conventional breeding schemes take many years and need a lot of space in greenhouses and/or in fields to achieve genotypes with the desired traits. We have improved the half-seed method that allows flax line selection from their oil seed composition. Cotyledon tips were analysed by GC to determine their FAME profiles while the remaining seed was sown to regenerate flax plant. An optimisation of the GC enabled a sample to be analysed every 4 minutes. Such a technique could be applied without loss of germination rate for excised seeds. Further experiments showed that both seed parts had the same fatty acid profile as cotyledon tips. This non-destructive procedure based on the half-seed method and ultrafast GC analysis provides an efficient screening of flax genotypes according to their seed fatty acid composition over only one generation.
Gas chromatography, oil flax, half-seed, screening, fatty acid profiles, linoleic acid
Stability analysis for yield and yield components over seasons in cowpea [Vigna unguiculata L. (Walp.)]
Twenty diverse genotypes including one local check (C-152) of cowpea were evaluated over three seasons to study the stability parameters viz., regression coefficient (bi) and mean square deviations (s2di) from linear regression along with per se performance for five yield related traits. Variances due to genotype, environment, genotype x environment, environment + (genotype x environment), environment (linear) were significant for pods per plant and seed yield per plant. Based on the stability analysis, the genotype IL3 was found stable across the seasons for test weight. Genotypes such as M17, Goa local and Bailhongal local were stable and superior across all the environments for seed yield.
Cowpea, regression coefficient, genotype, stability etc.
Combining ability analysis for yield and its component traits in Blackgram (Vigna mungo (L.) Hepper)
A diallele analaysis of 8 x 8 was studied in black gram (Vigna mungo) with a view to understand the combining ability, nature of gene action and potential for the exploitation of heterosis using nine quantitative characters viz., days to first flower, plant height, number of branches per plant, number of clusters per plant, number of pods per cluster, number of pods per plant, number of seeds per pod, hundred seed weight and seed yield per plant in 28 hybrids and their eight parents. The parent ADT 3 recorded relatively high per se performance for seed yield, hundred seed weight, number of clusters per plant, number of pods per cluster, number of pods per plant and number of branches per plant with early flowering and short stature. Among the hybrids, ADT 3/99V48, ADT 3/LBG 645 and 2KU 53/LBG 645 were found to have high mean performance for almost all the yield component characters besides seed yield. The gca effect of the genotypes ADT 3, LBG 645 and 2 KU 53 was high and significant for the traits seed yield per plant besides number of pods per cluster, number of pods per plant and number of seeds per pod. The SCA variance was greater than GCA variance for all the traits studied thus indicating the predominance of non-additive gene action. Among the hybrids, ADT 3/99V48 recorded the maximum significant sca effect indicating their suitability for heterosis breeding. The hybrids ADT 3/ LBG 645 and 2 KU 53/ LBG 645 recorded non significant sca effects for almost all the traits studied including seed yield per plant. Hence, these two crosses were adjudged as superior for recombination breeding based on sca effects.
Black gram, combining ability, gca, sca, per se performance, non- additive action
Pattern of diversity based on phenological and productivity traits in chickpea (Cicer arietinum L.)
One hundred twenty six Recombinant Inbred Lines (RILs) derived from a cross ICCV-2 x JG 62 along with six checks were evaluated to study the genetic divergence. Mahalonobis (1936) D2 statistic analysis was used for assessing the genetic divergence among the RIL’s involving phenological and yield component traits. The 132 genotypes formed 15 clusters and out of which 8 clusters were solitary suggesting the very diverse nature of 8 RILs from rest of the genotypes. But no distinct grouping of desi and kabuli types were observed indicating reasonably high degree of recombination between JG 62 and ICCV 2. The two solitary clusters, VIII and X showed their distinctiveness from the other groups as reflected by generally higher magnitude of inter cluster distance values of these two clusters with other clusters and are characterised by mean high pod number, seed yield and ideal duration of reproductive phase. As for degree of contribution of each character to divergence, the pods per plant contributed maximum (76.58%).
Chickpea, RILs (Recombinant Inbred Lines), diversity, clusters, Duration of Reproductive Period (DRP), phenological traits, productivity.
Genetic diversity among the land races of sorghum collected in Tamil Nadu
Sixty three local land races of sorghum (Sorghum bicolor L.) collected from different parts of Tamil Nadu were evaluated for their genetic diversity based on nine characters. The genotypes were grouped into 14 clusters indicating high genetic divergence among them. The study indicated no definite relationship between geographic and genetic diversity and geographic diversity cannot be used as an index of genetic diversity. Based on the inter cluster distance and cluster mean for various characters it could be seen that the clusters VI, X, XII were the most divergent from the other clusters. The genotypes from these parents possibly be utilized for hybridization programme. Days to flowering, plant height, ear head length and grain weight contributed highly towards the genetic divergence among the genotypes studied.
Sorghum, genetic divergence, inter cluster, cluster mean, contributed characters
DPO 14 - An early maturating mutant of Isabgol (Plantago ovata Forsk)
DOP-14 is an early maturing mutant of Isabgol. It has early maturing with desirable traits such as high seed yield, early & uniform seed maturation and high harvest index. It can be an important source for developing early maturing high yielding Isabgol varieties with desirable quality.
Genetic variability in coconut (Cocos nucifera)
Genetic variability analysis of morphological growth characters, nut yield and nut characters in twenty eight coconut genotypes revealed a high degree of variability for nut yield, whole nut weight, dehusked nut weight and copra weight. Nut yield exhibits positive correlation with number of functional leaves, length of leaves and petiole. Path coefficient analysis revealed that the direct effect of number of functional leaves on nut yield was positive and high followed by petiole length and leaf length. Thus, these characters are to be given importance for nut yield improvement in coconut.
A study of genetic diversity in 25 chilli genotypes for various characters revealed substantial differences for all the traits. Based on D2 values, the genotypes were clustered into eight constellations. Cluster I contained nine genotypes fallowed by cluster-II (four) cluster IV and V (two each). The maximum inter cluster distance (D=12.75) was observed between cluster VI and cluster VIII. The cluster IV recorded maximum intracluster distance (D=5.91).Intercrossing among the genotypes belonging to cluster III, IV and I was suggested to develop high yielding varieties with other desirable characters or may be used as potential donors for future hybridization programme to develop better chilli variety with good fruit yield.
Capsicum annnum, Genetic divergence, yield
Genetic variability studies in single and double cross advanced generation segregating progenies of Bhendi [Abelmoschus esculentus (L.)Moench]
An investigation was carried out to study the genetic variability, in fruit yield per plant and its component traits in four single cross (BH10,BH11,BH12 and BH 13) and three double cross (BH14,BH15 and BH16) F4 and F5 progenies of bhendi at ARS, Hanumanamatti during summer and kharif 2008. The results indicate that, high GCV and PCV values for number of branches per plant, number of fruits per plant and fruit yield per plant. Moderate GCV and PCV values were recorded for internodal length, fruit length, fruit diameter and fruit weight in both single and double cross F4 and F5 progenies which indicate existence of wide range of genetic variability in the material evaluated. High heritability coupled with high genetic advance was observed for number of branches per plant, number of fruits per plant and fruit yield per plant in both single and double cross F4 and F5 progenies indicating additive gene action in the control of expression of these characters. From the experimental results it was found that the amount of variability was more in double cross derived progenies as compared to single cross derived progenies for most of the characters studied.
Bhendi, single cross, double cross, genetic variability
Genetic Divergence Studies in Safflower, Carthamus tinctorius L.
The present study was carried out to study the genetic divergence among 75 germplasm lines of safflower. Analysis of variance revealed significant variation among the genotypes for all the characters studied. Among the genotypes, GMU 3327, GMU 3279, GMU 3325 and GMU 3313 were found to be promising on the basis of per se performance for seed yield. Seed yield exhibited maximum contribution towards genetic divergence followed by number of capitula per plant, number of seeds per capitulum, oil content, days to 50% flowering and days to maturity. The genotypes were grouped into 8 clusters out of which cluster II is having maximum of 23 genotypes followed by cluster I with 20 genotypes. Maximum inter cluster distance was observed between clusters VII and VIII followed by clusters VI and VIII, clusters IV and VIII and clusters I and VIII .