Influence of grape genotype, ripening season, seed trace size, and culture date on in ovule embryo development and plant formation

Abstract

Eighteen seedless grape genotypes differing in ripening season (early, mid and late) and in seed trace size (small, medium and large) were harvested at 6, 10, 14, 18 and 22 weeks past bloom (wpb). Using embryo rescue techniques it was studied if embryo do abort as the fruit matures and what percent embryos remain viable at later stages. The size of seed trace was also investigated to determine its influence on embryo viability during maturation. It was found that genotype have great influence on embryo culture traits. Late maturing genotypes showed fewer rescued embryos, germinated embryos and transplantable plants than early and mid season ones. The best culture time for grape embryo rescue is 6 and 10 wpb. At these dates, the largest number of embryos, germinated embryos and transplantable plants were obtained. Genotypes with the largest ratio for seed trace weight/seed trace length (i.e., largest density) showed the greatest tendency to have the largest number of ovules with embryos, more germinated embryos and more transplantable plants. The study also showed that it is possible to recover plants from mature fruit harvested late, although at a much reduced rate.

Immature Embryo Rescue and <i>in Vitro</i> Development Evaluation of Intraspecific Hybrids from Brazilian Seedless Grapevine “Superior × Thompson” Clones

“…The grape hybrids used in this study were derived from the "Thompson Seedless" and "Superior Seedless" Brazilian clones crossing, obtained from cultivated plants in an experimental field of Embrapa Tropical Semiarid, according to the procedures proposed by [7]. Eight weeks after the crossing, 152 ovules were collected from the obtained fruits, and inoculated into the culture media proposed by [8] under aseptic conditions.…”

Desarrollo de nuevas variedades de uva (Vitis vinifera L.) sin semilla mediante rescate de embriones

“…This efficiency can be altered as a result of time out after anthesis (García et al, 2000); growth regulators Nookaraju et al, 2007); grape variety used (Hewstone et al, 2006); intensity and type of pruning (Dalal et al, 1992;Ponce et al, 2009); genotype, harvest time and embryo size (Ramming and Emershad, 1990;Pommer et al, 1995) thus culture medium and time of in vitro culture (Valdez, 2005). Based on the above, the present study aims to evaluate the efficiency of embryo rescue technique in f1 individuals from hybridizations performed through classical genetic techniques using different varieties of seedless grapes.…”

“…Esta eficiencia puede alterarse como resultado del tiempo de espera después de antesis (García et al, 2000); reguladores de crecimiento Nookaraju et al, 2007); variedad de uva utilizada (Hewstone et al, 2006); intensidad y tipo de poda (Dalal et al, 1992;Ponce et al, 2009); genotipo, época de cosecha y tamaño del embrión (Ramming y Emershad, 1990;Pommer et al, 1995) así como el medio de cultivo utilizado y tiempo de cultivo in vitro (Valdez, 2005). Con base en lo anterior mencionado, el presente trabajo tiene como objetivo evaluar la eficiencia de la técnica de rescate de embriones en individuos f1 provenientes de hibridaciones realizadas mediante técnicas de genética tradicional utilizando diferentes variedades de uva sin semilla.…”

Hybrid Embryo Rescue in Crop Improvement

“…Results indicated that in ovulo embryo rescue can be improved by increasing CaCl2 concentration and incorporating casein hydrolysate supplement in the basal medium, by exploiting genotypic differences using seedless parents yielding higher proportions of rescued hybrids and, possibly, by understanding environmental effects on female parents to maximize the number of hybrids produced. Pommer et al ( 1995 ) used 18 seedless grape genotypes differing in ripening season (early, mid and late) and in seed trace size (small, medium and large) and harvested at 6, 10, 14, 18 and 22 weeks post-bloom (wpb). Using embryo rescue techniques, it was studied if embryos aborted as the fruit matured and what percentage of embryos remained viable at later stages.…”