Characterization of somaclonal variants of sugarcane on the basis of quantitative, qualitative, and genetic attributes

摘要

Somaclonal variation is an important tool for creating genetic diversity in sugarcane. Somaclones of NIA-1198 were developed through callus culture and subjected to field trials under randomized complete block design with three replications over two consecutive years (2013-14 and 2014-15). Crop was harvested after 12 months of planting each year and the quantitative and qualitative parameters were determined at harvesting stage. Quantitative traits included plant height, girth, tillers, internode length, number of internodes, stool weight, and cane yield, whereas qualitative parameters included CCS%, brix %, sucrose %, fiber %, purity, sugar recovery, and sugar yield. The data of both cropping seasons were pooled and subjected to statistical analysis and other tests. Statistically significant differences were observed for all the characteristics among somaclonal population. Somaclone SC8 was observed to have highest cane yield of 77.87 t/ha against the 64.87 t/ha of the parent. While, somaclone SC30 exhibited highest sugar yield of 11.58 t/ha as compared to the parent’s 7.86 t/ha. Sugar recovery was also observed to be maximum for the SC30 (14.42%). SC12 somaclone presented highest cane height of 372 cm whereas maximum number of tillers were harvested in SC13, and SC30 (9.0). On comparing the somaclones for percent variation, highest range of variation was recorded for sugar yield which increased as much as 47.5 % in some of the somaclones whereas it decreased up to -55.7 % in others. Cluster analysis of the parameters classified the genotypes into five major clusters. Only 4 somaclones were observed to appear with the parent (NIA-1198) in the same cluster. Cluster 1 was distinguished by highest quantitative traits, cluster 2 was characterized by maximum qualitative parameters, and cluster 5 recorded highest fiber contents. Pearson’s correlation analysis showed strong correlation of cane yield with the cane girth (0.536), and tillers per plant (0.607). Whereas, sugar yield was observed to have highest correlation with cane yield (0.814), CCS % (0.604) and sugar recovery (0.596). On principal component analysis (PCA) of the pooled data, parameters under study were observed to divide into five principal components (PCs) which contributed for up to 93.18% variability. Many of the somaclones were observed to be placed on high distances from each other on the score plot of PCA. Genetic parameters of the somaclonal population showed that the characteristics under study were highly heritable, and possessed low environmental variance. The heritability values for all the characters were estimated to be more than 93% at least. It can be concluded from the study that somaclonal variations can create highly diverse populations of sugarcane for evaluation in cane breeding programs.