Chandra Visalakshi, Sheela M N, Ravi V, Gurung Bishal, Sankar Senthil Alias, Sreekumar J
ICAR- Central Tuber Crops Research Institute, Sreekaryam, Thiruvananthapuram, Kerala, India.
ICAR-Indian Agricultural Statistics Research Institute, New Delhi, India.
Biochem Genet. 2024 Nov 18. doi: 10.1007/s10528-024-10972-6.
The study aimed to estimate the genetic parameters and predict the genotypic values of postharvest physiological deterioration and root characteristics in cassava (Manihot esculentaCrantz) using restricted maximum likelihood (REML) and the best linear unbiased prediction (BLUP). A total of 76 cassava accessions were evaluated over two growing seasons. The evaluated traits included postharvest physiological deterioration response (PPD), root length (RL), root diameter (RD), root weight (RW), dry matter content (DMC), total starch content (TS) and total sugar content (TSU). All the traits had a higher phenotypic variance component than genetic or environmental variance, with genotypic variance making up a larger portion of the total phenotypic variance. Heritability estimates ranged from low to high, with high heritability values being recorded for dry matter content, PPD, and root diameter. The study discovered high genotypic coefficients of variation (CVg) for PPD, root weight and diameter, indicating strong genotypic variability beneficial for selection. As larger genetic effects than non-genetic effects lead to increased selection gains, the highest CVr values for dry matter content and PPD suggest the biggest probability of selection gain. Postharvest Physiological deterioration (PPD) had the highest genetic advance, indicating significant gain in the following generation. Thirty eight genotypes were selected as the most promising based on BLUP index, promoting improvement and genetic gain in several traits. The genotypes selected can be included in cassava breeding programs for PPD tolerance and other tuber traits.
本研究旨在利用限制最大似然法（REML）和最佳线性无偏预测法（BLUP）估计木薯（Manihot esculenta Crantz）采后生理劣变和根系特征的遗传参数，并预测其基因型值。在两个生长季节对总共76份木薯种质进行了评估。评估的性状包括采后生理劣变反应（PPD）、根长（RL）、根直径（RD）、根重（RW）、干物质含量（DMC）、总淀粉含量（TS）和总糖含量（TSU）。所有性状的表型方差分量均高于遗传方差或环境方差，其中基因型方差在总表型方差中占比更大。遗传力估计值从低到高不等，干物质含量、PPD和根直径的遗传力值较高。该研究发现PPD、根重和直径的基因型变异系数（CVg）较高，表明存在有利于选择的强基因型变异性。由于遗传效应大于非遗传效应会导致选择增益增加，干物质含量和PPD的最高CVr值表明选择增益的可能性最大。采后生理劣变（PPD）的遗传进展最高，表明下一代有显著增益。基于BLUP指数选择了38个最有前景的基因型，促进了多个性状的改良和遗传增益。所选基因型可纳入木薯育种计划，用于培育耐PPD和其他块根性状的品种。
