The present study was conducted at the research farm of Dryland Agriculture Research Station, SKUAST-Kashmir during the kharif of 2019. Range of heterosis was calculated over standard check. The most desirable cross combinations viz., KDM-440 x KDM-914A (-5.879), KDM-440 x V-335 (-4.468), KDM-930 x V-351(-4.165), KDM-927A x V-335 (-3.986), CML-470 x KDM-914A (-3.808) for days to maturity, KDM-347 x V-351 (4.967) CML-470 x KDM-914A (4.610), CML-474 × V-351(-4.396), KDM-927 A x V-351 (-3.110), KDM-930 x V 335 (2.896) for number of kernel rows per cob, KDM-347 x V-351(-7.544), KDM-440 x V-351 (6.438), KDM-916A x KDM-914 A(6.117), CML-470 × V-351(5.992), CML-474 x V-335 (5.274) for number of kernels per row, KDM-340 x V-351 (3.966), KDM340 x KDM-914A (3.150), KDM-930 x V-351(3.165), KDM-440 x KDM-914 (3.556), KDM-347 x V-351(3.324) for 100-grain weight, KDM-347 x V351 (34.197), KDM-440 x V335 (28.933), CML470 x KDM-914A (29.380), KDM-895 x KDM914A (25.383), KDM927A x KDM-914A (19.549) for grain yield per plant were observed in the present study. The range of heterosis  over  standard check for days to maturity from -3.796 (CML-425 × KDM-914A) to (2.414) CML-474 × KDM-914A. The extent of heterosis for number of kernel rows per ear over standard check ranged from CML-470 x V-335(28.576) to KDM-916A × V -335(-2.143), for quantity of kernels per row maximum well known heterosis ranged from CML-470 × V-351 (19.079) to KDM-347 × V-351 (-15.132), for 100- grain weight, heterosis ranged from 22.3% for CML-470 x KDM-914 A  to -3.5% for KDM-916A × V-335. For grain yield per plant, heterosis ranged from 61.9% for CML-470 x K DM-914 A to 9.3% for KDM916A x V-335. Standard  heterosis for crosses CML -470 × KDM-914 A, CML-474 × V-351, KDM-440 × V-335 should be tested for multilocation to make valid conclusion related to their use in commercial maize cultivation.

The decline in tropical maize productivity due to climatic vulnerability is a matter of serious concern as being a food and feed/fodder commodity, it is an important crop for the sustenance of human life. Genetic selections and development of water deficit stress (WDS) tolerant commercial varieties have potential to offset the impact of changing temperatures and precipitation. For trait-specific genetic enhancement, there is a need to understand a suite of adaptation strategies for crop. We studied the response of various shoot and root traits in 71 maize inbreds of diverse origin under simulated sub-optimal water supply controlled conditions, delineated an array of traits which must be considered for selection for WDS and validated the inbreds harbouring tolerance to WDS for selection of authentic donor lines to develop WDS tolerant hybrids. A large data set was limited to uncorrelated traits based on principal component analysis and variability among maize lines was deciphered using heatmap dendrogram. We also reported the relevance of root anatomical plasticity to the inherent potential of lines to combat WDS. We recommend incorporating the changes in number and diameter of xylem and metaxylem under simulated controlled conditions as a part of precise phenotyping for WDS in maize. The study led to identification of WDS tolerant line LM22 in maize.

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