The reproductive biology of okra. 2. Self-fertilization kinetics in the cultivated okra (Abelmoschus esculentus), and consequences for breeding

Abstract

The use of Cruden's index (1977), for studying okra sexual reproductive allocations, indicates a facultative autogamy mode . The purpose of the research described is to obtain more accurate information on the self-fertilization process . For this, self-pollen grain germination was stopped at different times of the day . Twelve varieties of Abelmoschus esculentus were used . Self-fertilization kinetics -expressed by the setting rate -displayed an increase between 7 .00 to 16 .00 hr. Study of obtained progenies, by stimulated allogamy, confirmed the process and showed that allo-pollen grains deposited on a stigma after midday had only a very little chance of contributing to fertilization . As a result, the polymorphism of the flower structure and particularly the distance between anther and stigmas, insect types and movement habits play major roles in governing okra allogamy . We also show that self-fertilization kinetics can be used to improve controlled hybrid production .

Screening of Microsatellite Markers for Genetic Diversity Assessment and Conservation of Germplasm in Okra (Abelmoschus esculentus L. Moench)

“…Combinations generated by okra genotypes, the maximum similarity (0.958) were found between the 282-10-1 and 167 and lowest similarity (0.50) were observed 454-10-1. High similarity among the accessions studied was expected because okra has highly self-pollinated species (Hamon and Koechlin, 1991) and similar results were also reported by Gulsen et al, (2007) and Sharma et al, (2015) who has also observed 100 % similarity in cultivars among the grapefruit cultivars…”

Diversity and relationships among Turkish okra germplasm by SRAP and phenotypic marker polymorphism

“…The second group contained two identical genotypes, 97 and 98. High similarity among the genotypes studied was expected because okra has heavily self pollinated species (Hamon & Koechlin 1991). The remaining 17 genotypes including two outgroups were distinguished from one another.…”

“…Okra flowers are hermaphoroditic and heavily self-pollinated. Cross-pollination also occurs depending on frequency of pollen transfer by insects (Hamon & Koechlin 1991). This outcrossing of okra ensures diversity that provides valuable opportunity for further okra improvement and help extended adaptability for local okra genotypes.…”

Molecular systematics of Abelmoschus (Malvaceae) and genetic diversity within the cultivated species of this genus based on nuclear ITS and chloroplast rpL16 sequence data

“…To a lesser degree (only for ITS) this was also true for A. moschatus. However, this may be the consequence of the more advanced domestication process in A. esculentus; in A. manihot and A. moschatus, wild populations are widespread (Charrier 1984) and might exchange genetic material with cultivated plants as these species seem to be facultative outbreeders (Hamon and Koechlin 1991). It is known that the domestication process frequently leads to bottlenecks in genetic diversity (Buckler et al 2001).…”