Study On The Seed Vivipary Characteristics Of Common Bean (Phaseolus Vulgaris L.)

In the present study, various common bean (Phaseolus vulgaris L.) cultivars were used to investigate the period during which vivipary seed happened, and frequency of vivipary seed under different cultivated conditions. Anatomical characteristics of pod were conducted during pod development with three cultivars which were quite different in vivipary trail. The possible relationship between seed vivipary and seed germination, protein during seed development was carried out with various common bean cultivars. In order to study the inheritance of seed vivipary, two F₂ populations which derived from cultivars differed in seed-coat color and seed vivipary were used to investigate the seed vivipary of individual plant. The main results were summarized as follows:It was found that seed vivipary did not occurred until 35 days after flower whether under open field or greenhouse condition. Vivipary seed percent varied with cultivars and growth conditions. The percentage of vivipary seed in open field was higher than in greenhouse, because of its relative high humidity under open field. There was a close relationship between the seed-coat color and the percentage of vivipary seed, i.e. vivipary seed pecent of white-coat seed was much higher than that of colored seed. Under favorable condition, seed had germinated ability even 20 days after flower, with the seed growth seed germination percent was increased, and then decreased when seed developed to 30-35 days after flower. Experimental data showed changes of seed germination during pod development were affected by growth condition. The possible explaination of decrease of seed germination ability was characteristic of seed dormancy when seed developed to a certain degree. This characteristic of seed dormancy varied with cultivars, i.e. the higher the percentage of vivipary seed, the later the seed dormancy occurred.Anatomical study showed that cultivars which were differed in seed vivipary had the similar basical pod structuer at the same development stage. During the pod development, all cultivars had the same dynamic of pod structure, the thickness of epidermit, thick-walled cell layer and thin-walled cell layer increased with the pod development, and reached the maximum level at 30 or 33 days after abloom, and then decreased. The soft tissue of pod vanished gradually with the seed development, and the cell wall of suture cutinized gradually. On the other hand, different cell forms of thin-walled cell were observed with different cultivars which varied in seed vivipary characteristic, the thin-walled cell of cultivar resistanted to seed vivipary was in round form, on the contrary, the thin-walled cell of cultivars which were easy to vivipary was rectangular. Suture length, width and the distance to thin-walled cell of cultivar resistanted to vivipary were longer or wider than that of cultivars which were easy to vivipary.With the pod development, soluble protein content in pod increased except cv. 6, and it was increased steadly in seeds. Special globulin bands were detected not only during different seed development stages but also among different cultivars by SDS-PAGE, moreover special globulin bands were found before or after seed vivipary. However, whether these special globulin were related to seed vivipary remain futher study.Experiment data verified that seed vivipary characteristic of common bean was able to inherit from parent to progeny by sexual process. The seed vivipary of two F2 populations derived from parents differed in seed vivipary was investigated individually, it was found that percentage of vivipary seed on F2 population was inclined to maternal which was easy to vivipary, the distributions of seed vivipary percent of single plant were continuously of both F2 populations. All these results showed the characristic of seed vivipary belonged to quantitative inheritance. Special protein bands in both parents and F2 plants which were differed in seed vivipary percent were detected though these special bands reflected the vivipary character was not confirmed.