Effect of gamete selection in improving of heat tolerance as demonstrated by shift in allele frequency in maize (Zea mays L.)

• Published in: Euphytica 2020-05, Vol.216 (5), Article 76
• Main Authors: Mohapatra, Upasana, Singh, Ashutosh, Ravikumar, R. L.
• Format: Article
• Language: English
• Subjects: Alleles; Analysis; Biomedical and Life Sciences; Biotechnology; Corn; Crop yield; Diploids; Gene frequency; Genotypes; Heat stress; Heat tolerance; Heat treatment; Life cycles; Life Sciences; Plant Genetics and Genomics; Plant Pathology; Plant Physiology; Plant Sciences; Pollen; Population; Population genetics; Populations; Self-fertilization
• ISSN: 0014-2336; 1573-5060
• DOI: 10.1007/s10681-020-02603-z

Pollen genotype selection for genes expressed in both the haploid and diploid phases of the plant life cycle can lead to correlated responses detectable in the sporophyte. Here, Impact of pollen selection for heat tolerance was assessed in segregating population of maize. Two subsets of F 1 were made among which one was self-fertilized with heat treated pollen grains while other set by normal pollen where no such selection was made that resulted in two F 2 populations TF 2 and CF 2 , respectively. The TF 2 population recorded significantly higher mean values for pollen per anther (4646.78 ± 176.70) than that for control F 2 population (3321.89 ± 164.91). In addition, the test F 2 population recorded significantly higher seed yield per plant (2.02 ± 0.72 g) than that of test F 2 population (1.38 ± 0.08 g) under heat stress. These two populations were also evaluated under normal condition to verify whether the TF 2 population showed heat tolerance improvement has any impact on yield attributes. The result showed non-negative impact of pollen selection on performance of TF 2 under normal condition. Thus, pollen selection could be used to selectively improve the trait of interest. The segregation analysis of SSR markers followed the expected Mendelian distribution in CF 2 population whereas a significant deviation in allelic frequency was observed in TF 2 population. These results clearly evidence that the gametophytic selection for heat tolerance in F 1 generation had positive effect towards increasing the resistant alleles in F 2 population of maize.