Genetic diversity assessment of extant cotton varieties based on Principal Component Analysis (PCA) and cluster analysis of enlisted DUS traits
Morphological characterization of 47 tetraploid cotton varieties cultivated in different zones of India was carried out over two seasons. The lay out followed randomized block Design and evaluation was done using 36 DUS descriptors in two replications. The visual characters showed uniform expression within the variety for two consecutive years indicating that they were uniform and stable in expression. Eleven out of 37 traits were monomorphic among the varieties. The remaining 26 characters were used for Principal Component Analysis to find the contribution of traits towards total variability. The PCA identified a total of 10 Components with Eigen values more than 1 contributing to a cumulative 77.74 % variability. The first component (PC1) exhibited maximum variability and highly correlated with traits such as leaf shape and petal spot which are also included in the grouping characters of DUS test guideline. The scatter diagram drawn using first two principle components with highest variability as well as the hierarchical cluster analysis performed using all the ten components distinctly classified genotypes in a consistent manner. The grouping of genotypes was attributed to relatively high contribution from few characters or variables which had high positive loadings, distributed among first two components rather than small contribution from each character.
It is certified that:
- The corresponding author is fully responsible for any disputes arising due to the publication of his/her manuscript.
- The article has been seen by all the authors who are satisfied with its form and content.
- The sequence of names of authors in the by-line is as per their relative contribution to this experiment, giving due credit to all scientists who made notable contribution to it.
- All the authors fully understand that inclusion of any other co-authors or exclusion of any co-authors is not possible once the article has been submitted to the journal.
- The corresponding author takes full responsibility for this article.
- The address of the organization where the research was conducted is given.
- The article is exclusive for this journal, and the results reported here have not been sent (and will not be sent during its consideration by this journal) for publication in any other journal.
- Authors agree to abide by the objective comments of referees and do agree to modify the article into a short note as per the recommendation, for publication in the Electronic Journal of Plant Breeding.
- If published in Electronic Journal of Plant Breeding, the copyright of this article would vest with the Indian Society of Plant Breeders, who will have the right to enter into any agreement with any organization in India or abroad engaged in reprography, photocopying, storage and dissemination of information contained in it, and neither we nor our legal heirs will have any claims on royalty.