Trait Specific Recombinant Inbred Lines for High Temperature Tolerance in Finger Millet

摘要

Agriculture production and productivity are adversely affected due to increasing episodes of high temperature and drought in the changing climate scenario. Finger millet is relatively a drought-tolerant crop but is sensitive to high temperature because it originated in the cool climate of the highlands in Africa. Identification of varieties for high-temperature adaptation could serve against the rising temperature and considering its nutritional importance, the crop can be extended to the non-traditional high-temperature regions. One of the approaches for identifying a genotype tolerant to high temperature could be by exploiting available genetic resources like germplasm lines. However, the use of a stable mapping population is better in identifyingbetter lines over the better parent. Therefore, a study was conducted using 222 recombinant inbred lines (RIL’s; F_6) developed for high-temperature tolerance. Differences in temperatures during the crop growth period were achieved by adopting two dates of sowing. The study showed a 1.4 °C rise in temperature during the vegetative to the flowering stage that resulted in a significant decrease in days to flowering, leaf chlorophyll content, the number of productive tillers, mean ear weight, threshingpercentage, and grain yield. Correlations showed a significant positive relationship between SCMR, leaf thickness, productive tillers, mean ear weight and threshing percentage with the grain yield under high-temperature condition. Whereas, a significantnegative relationship was observed for grain yield with days to flowering and leaf temperature under HT conditions. The principal component analysis (PCA) also showed that grain yield and the number of productive tillers were the most contributing factors to variance. Based on these two traits, significantly HT tolerant RILs over the better parent, PR-202 (PT, 111.2 ± 1.22/m~2 and grain yield, 263.2 ± 3.44 g/m~2) are 6.2.5, 6.5.7, 6.3.9, 6.2.25 and 6.19.15, which can be used in crop improvement or fordirect cultivation.