EFFECT OF DROUGHT TOLERANT QTLs ON YIELD AND YIELD CONTRIBUTING TRAITS UNDER MANAGED WATER STRESS AS WELL AS NON STRESS CONDITION
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Date
2011
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Publisher
Indira Gandhi Krishi Vishwavidyalaya, Raipur
Abstract
The complex nature of drought tolerance, genotype x environment interaction, lack of understanding of inheritance of drought tolerance, poor understanding of physiological basis of yield under water limited condition and difficulty of effective drought tolerance screening complicate the development of drought tolerance varieties. Therefore, the present study was undertaken to carry out the genetic analysis for understanding the genetics basis of drought tolerance and identification of QTLs for yield and yield contributing traits under water stress condition. The analysis of variance indicated substantial variation among the 77 lines for grain yield and yield contributing traits. Significant variation was noticed among the 77 lines for grain yield and yield contributing traits under irrigated as well as TSD situation. The mean grain yield of these lines was higher in irrigated as compared to TSD condition, respectively, indicating very high level of stress. The presence of QTL‟s has increased the plant height and also it has resulted increased yield under stress condition which is a major advantage.. The increase in the plant height because of DT QTL‟s under irrigated condition results in lodging of these lines which become a major disadvantage. The estimates of correlation showed highly positive and significant association between grain yield, harvest index and biological yield under both irrigated as well as terminal stage drought condition. The estimates of direct effect showed that biological yield had significant direct effect and exhibited positive correlation with grain yield under both the conditions. The major QTLs showed low and variable effect in the background of improved mega varieties, the targeted cultivars for improving drought tolerance. Recently, two major QTLs, one each in the background of mega varieties „Swarna‟ and „IR 64‟ have been identified.
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Keywords
QTLs, YIELD, YIELD CONTRIBUTING TRAITS, MANAGED WATER STRESS
Citation
130 p.