Genotypic variation in intrinsic transpiration efficiency correlates with sugarcane yield under rainfed and irrigated field conditions.
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ABSTRACT: Intrinsic transpiration efficiency (i TE), the ratio of photosynthesis (A) to stomatal conductance (gs ), is considered a useful trait for improving productivity; however, higher i TE with high A is more desirable than that with low gs . This study dissects i TE of 20 sugarcane genotypes to understand its relationship with total dry matter (TDM) and cane yield (TCH) under irrigated and rainfed conditions. Water stress reduced mean A and gs by 56 and 61%, and mean TDM and TCH by 55 and 59%, respectively; however, genotype × irrigation treatment interaction was smaller than genotype variance. Mean i TE increased from 117.4 μmol mol-1 in the irrigated treatment to 130.6 μmol mol-1 in the rainfed treatment. In irrigated conditions, i TE had high heritability (H2 b = 0.67) and significant genetic correlation with TDM (rg = 0.58) and TCH (rg = 0.72). Under water stress, at gs below 0.1 mol m-2 s-1 , non-stomatal limitation to A was evident and i TE had low heritability (H2 b = 0.2). Whereas in the gs range of 0.1-0.4 mol m-2 s-1 , heritability of i TE (H2 b = 0.63) and its genetic correlation with TDM (rg = 0.78) and TCH (rg = 0.75) were maximised. There was significant genotypic variation in photosynthetic capacity (Ac ), and the differences were related to TDM and i TE. Selecting genotypes with higher i TE and Ac could offer potential for improving productivity without the unfavourable effect of low gs .
SUBMITTER: Natarajan S
PROVIDER: S-EPMC8247395 | biostudies-literature |
REPOSITORIES: biostudies-literature
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