Cultura de tecidos e cruzamentos interespecíficos visando obtenção de haploides em meloeiro

Abstract

For melons, a haploid selection technique is somewhat affordable, as a very long power source uses energy sources that are seriously harmful to living organisms and extremely high dose doses. On the other hand, it is able to detect haploids by alternative methods, such as in vitro culture of anthers or ova and interspecific crosses. Simultaneously, it is an efficient protocol for the multiplication of haploid and dihaploid individuals, avoiding a premature loss of promising genotypes. In this context, we sought to: I - determine a protocol to establish the in vitro culture of melon, defining the most recommended explant, both for micropropagation and for a culture androgenesis; II - to evaluate the efficiency of haploidization anthers and drawers in vitro by means of indirect organogenesis and embryogenesis, respectively; III - define a cucurbit species capable of inducing a haploid formation in the three commercially cultivated botanical varieties of melon. The most probabilistic for the initial phase of the in vitro culture was the one that the tendon took as explant, disinfected with ethanol 70% (1 min) + sodium hypochlorite (NaClO) and 0.1% active chlorine (7.5 min) , followed by three rinses in autoclaved distilled water for one minute each. The flowers collected in pre-anthesis should have greater potential for an androgenesis of the crop, through different levels of contamination and loss of pollen grains during the disinfestation process. Calogenesis from germination and anthers of yellow melon was influenced by the distinct form of growth regulators in both organogenesis and somatic embryogenesis with calli obtained from anthers with potential for the formation of somatic embryos. As for interspecific crosses, of the 11 cucurbits evaluated only the pollen of zucchini and melon-de-são-caetano were able to stimulate a formation of melon fruits, and only in the crossbreeding between the zucchini and the inodorus and reticulatus varieties there was a formation of embryos with haploid characteristics When the pollen from the cucurbit was mixed with the pollen of the recipient plant, a new fruit of all treatments, however, there was no formation of haploid seeds. Zucchini and melon-de-são-caetano are able to form parthenocarpic fruits in melon. However, only in the crosses with soybean seeds with typical haploid characteristics.