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Genetic evidence of pollen selection mediated phenotypic changes in maize conferring transgenerational heat‐stress tolerance
Author(s) -
Singh Ashutosh,
Antre Suresh H.,
Ravikumar Rampura Laxmipathi,
Kuchanur P. H.,
Lohithaswa Hirenallur Chandappa
Publication year - 2020
Publication title -
crop science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.76
H-Index - 147
eISSN - 1435-0653
pISSN - 0011-183X
DOI - 10.1002/csc2.20179
Subject(s) - pollen , biology , selfing , selection (genetic algorithm) , heat stress , botany , seedling , allele , inbred strain , horticulture , genetics , gene , population , zoology , demography , artificial intelligence , sociology , computer science
Structural genes of pollen are expressed in both sporophytic and gametophytic generations. This genetic overlap makes possible superior pollen genotype selection. Pollen selection is more effective than sporophytic selection since more pollen grains can be exposed to selection pressure at the haploid level. In this study, selection pressure was applied in the F 1 generation at the pollen level for heat tolerance. The frequencies of heat‐tolerant plants were studied for seed yield in F 2 and F 3 generations and for seedling heat tolerance in F 4 generations. The heat‐susceptible inbred line BTM4 was crossed to heat‐tolerant inbred line BTM6 of maize ( Zea mays L.). In response to heat stress, we compared F 2 plants produced by selfing of heat‐stressed pollen grains and without heat‐stressed pollen grains. The resulting F 2 plants from heat‐stressed pollen grains showed significantly higher seed yield per plant (5.41 ± 0.31 g) than control F 2 (2.90 ± 0.19 g) populations under stress. The selected and control F 2 plants were also subjected to genotyping using simple sequence repeat (SSR) primers. We observed that the frequency of alleles from tolerant parents was higher in selected F 2 populations, providing genetic evidence for positive effect of pollen selection. The heat tolerance of F 4 generation progenies of the same cross suggested that the cyclic pollen selection for heat tolerance in F 1 , F 2 , and F 3 generations has significantly improved the tolerance of progenies. The results from this study demonstrate that the feasibility of this approach seems to be promising for hastening the incorporation of desirable alleles in a short time.