Studies on development of abiotic stresses tolerant hybrids in maize (Zea mays L.)
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Date
2008-03
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G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand)
Abstract
The present study was undertaken on maize (Zea mays L.) in three conditions viz., normal, low-N and Excess Soil Moisture (ESM) during 2007 with the main objectives of (i) studying intercharacter correlations, (ii) estimating yield reduction under low-N and ESM conditions, (iii) examining the combining ability of parental lines and hybrid combination (iv) developing suitable selection indices in relation to low-N and ESM tolerance. The experimental material consisted of twelve lines and four testers and their 48 single crosses planted in Randomized Block Design. Analysis of variance revealed significance for all the traits studied in both conditions in all environments, clearly indicating there by the existence of high genetic variability in the genotypes.. Reduction in yield was comparatively lower in tolerant genotypes in all environments under field conditions. Parents L2, L7, L9, L10, L12 and T1 were the best general combiners for earliness in both low-N and ESM conditions. Crosses L2T4, L4T3, L5T2, L7T4, L8T1, L8T2, L9T1, L12T3 and L12T4 showed good GCA for ASI and L1T3, L2T4, L4T1, L5T2, L5T3, L6T2, L6T3, L7T2 , L8T1, L9T2, L10T1, L11T3, L11T4, L12T3 and L12T4 were good combiners for yield and crosses L2T2, L4T4, L5T2, L7T1, L10T1, L10T4, L11T3 and L12T4 were observed to be high combiners for 100-kernel weight in both low-N and ESM conditions. Yield was positively and significantly correlated with plant height, ear height, cob length, cob diameter and 100-kernel weight in both the conditions. However in case of low-N condition yield was also positively correlated with leaf senescence. Positive correlation of yield was also found with nodes bearing adventitious roots in ESM conditions. Crosses L11T4 and L6T4 had the highest index value in relation to low-N and ESM conditions respectively.
Description
Thesis-PhD
Keywords
abiotic, stress analysis, hybrids, maize, Zea mays, moisture content, soil water, combining ability