Abstract
A precocious flowering system of regenerants in asparagus (Asparagus officinalis) was achieved by treatment with a chemical inducer. Somatic embryos withered completely by being processed for 8 - 12 days with 200 μM n-propyl N-(3,4-dichloro-phenyl)carbamate that had been dissolved in distilled water. In contrast, precocious flowering occurred at an extremely low rate (3.4%) when somatic embryos were processed in carbamate dissolved in Murashige and Skoog’s liquid medium. To encapsulate the female and male embryos, we surveyed the optimum conditions of viscosity and concentration of sodium alginate for encapsulating the seeds, and we screened the values of 80 - 120 cps and 2% - 3%, respectively. The synthetic seeds produced also withered when they were processed with the carbamate dissolved in distilled water. However, when Murashige and Skoog’s liquid medium was used for the solvent, the flowering frequency of the synthetic seeds was enhanced (13.3%). Based on our morphological and histological observations, female and male regenerants that were processed with the carbamate solution produced individual flower organs. The conversion of sex expression did not occur. A precocious flowering system would allow a significant reduction in the time required for perennial seedlings to flower and can, therefore, save time required for further experiments that employ floral homeotic mutants.
Highlights
The somatic embryos withered completely regardless of the concentration of carbamate when they were processed under optimum conditions for early flowering of seedlings, that is, when redifferentiated individuals were processed for 8 - 12 days with 200 μM carbamate dissolved in distilled water (Table 2)
Somatic embryos flowered precociously at a low frequency (3.4%) when they were directly treated with carbamate dissolved in Murashige and Skoog (MS) basal medium
It was reported that the frequency of embryogenesis could be controlled by alteration of the concentration of sugars and basal medium in order to produce encapsulatable units [30], and that vigorous embryos were obtained by treatment with plant growth regulators such as IAA, kinetin, ancimidol and ABA [31]
Summary
The flowers start their development as hermaphrodites that later become unisexual. The development and specification of flower organs are controlled by a limited set of genes. Mutant studies of Arabidopsis and Antirrhinum produced the ABC model of floral organ determination, in which there is combinatorial action of three regulatory functions [3]. The study of the molecular genetic mechanisms that control flower development in asparagus has advanced recently [8]-[16]. Toward a confirmation of the functional analyses of isolates, it was hoped that the transgenic asparagus plant could be brought out to early flowering for estimation of its morphological and histological aspects, since asparagus usually requires several years from seed to flower
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
