Effects of low temperatures on sexual reproduction of 'Tainong 1' mango (Mangifera indica).
Huang JingHao, Ma WeiHong, Liang GuoLu, Zhang LingYuan, Wang WeiXing, Cai ZiJian, Wen ShouXing
Author Affiliation: Pomological Institute, Fujian Academy of Agricultural Sciences, Fuhzou 350013, China.
Scientia Horticulturae 126 : 109-119
Abstract : Prevailing ambient temperature during the reproductive phase is one of important factors for seed and fruit set in different plant species. In mango (Mangifera indica L.), natural low temperatures during flowering induced seedless fruits. Here the sexual reproduction process of 'Tainong 1' mango at low temperatures (diurnal maximum temperature 20°C) was studied. For comparison, we also examined this process at normal temperatures (diurnal maximum ranging from 25 to 30°C, diurnal average temperature >20°C). Results showed: natural low temperatures significantly affected pistil and male gametophyte development, resulting in pollen grains with low viability. Meiotic chromosomal irregularities, including univalents, multivalents, laggards, bridges and micronuclei were detected at higher incidences and significantly greater proportions of nucleolus fragmentation and dissolution were detected when temperatures were low. Pollen tube growth was retarded under low temperature stress, either in vivo or in vitro. The virtual absence of sexual reproduction of 'Tainong 1' mango at low temperatures appears to be due largely to slow growth of pollen tube in vivo and to a low rate of successful fertilization.