The effect of 80 mmol•L-1 stress by excess of calcium nitrate [Ca(NO3)2] on biomass production, oxidative damage, antioxidant enzymes activities and polyamine contents in leaves of grafted and non-grafted eggplant (Solanum melongena L.) seedlings were studied, in which grafted plants were grafted on a salinity tolerant rootstock (Solanum torvum Swartz). The results showed that on the 15th day of treatment, the biomass production reduction of non-grafted seedlings was significantly higher than that of grafted seedlings. Under stress by excess of Ca(NO3)2, superoxide anion radical (O2•¯) producing rate, electrolyte leakage percentage, contents of hydrogen peroxide (H2O2) and malondialdehyde (MDA) of non-grafted seedlings were significantly higher than those of grafted seedlings, but activities of superoxide dismutase (SOD, EC 1.15.1.1), peroxidase (POD, EC 1.11.1.7), ascorbate peroxidase (APX, EC 1.11.1.11) and glutathione reductase (GR, EC 1.6.4.2) of grafted seedlings were significantly higher than those of non-grafted seedlings, moreover, contents of free, soluble conjugated and insoluble bound polyamines of grafted seedlings were significantly higher than those of non-grafted seedlings, and activities of diamine oxidase (DAO, EC 1.4.3.6) and polyamine oxidase (PAO, EC 1.5.3.3) of grafted seedlings were significantly lower than those of non-grafted seedlings. The possible roles of antioxidant enzymes and polyamines in protective mechanism of grafted eggplant seedlings to stress by excess of Ca(NO3)2 were discussed.

A pot culture experiment of nitrogen forms (NO3-:NH4+) with four ratios (100:0, 75:25, 50:50, and 25:75) in nutrient solutions was conducted to examine the effect of nitrogen forms on the growth and polyamines contents of developing seeds of vegetable soybean [Glycine max (L.) Merr. cv. Li-xiang 95-1]. Results showed that the best plant growth vigor was observed in NO3- (75%), and then in NH4+ (50%). However, the fresh and dry weight of biomass decreased when a high concentration of either NO3- (100%) or NH4+ (75%) was the primary nitrogen source in the nutrient solution. The numbers of flowers and pods in NH4+ (75%) were significantly decreased compared with other ammonium-nitrate ratios in which the numbers of flowers and pods were not influenced by nitrogen forms. During the development of seeds, levels of free Put and Spd decreased, and the decrease extents were more marked in 100:0 and 25:75 (NO3-:NH4+), but the change of free Spm was opposite. Levels of conjugated and bound polyamines in all nitrogen forms increased, but the increases in 75:25 and 50:50 (NO3-:NH4+) were not so obvious as in 100:0 and 25:75 (NO3-:NH4+) treatments. The possible roles of polyamines in the adaptive mechanism of vegetable soybean seeds to different nitrogen forms were discussed.

To establish a highly efficient system for shoot regeneration in vegetable soybean (Glycine max (L.) Merrill), explants were obtained from six genotypes and adventitious shoots were regenerated from cotyledonary nodes cultured on medium supplemented with different concentrations of N-phenyl-N′-1, 2, 3-thiadiazol-5-ylurea (thidiazuron TDZ) and 1-naphthylacetic acid (NAA). The most effective combination of plant growth regulators was selected first and then the effects of medium types, inoculation methods and genotypic differences on shoot regeneration were studied. The explants were inserted either vertically or horizontally into the medium and five basal media, including B5, ½ B5, MS, ½ MS, and MSB (MS salts and B5 organics), were tested. The shoot regeneration frequency of the six genotypes ranged from 53.5% to 88.9% and three of them reached 88.9%, 87.5% and 83.3% respectively on B5 medium supplemented with 1 mg•L-1 TDZ, 0.05 mg•L-1 NAA, and 5 mg•L-1 AgNO3. The shoot regeneration frequency of explants cultured on B5 medium was significantly higher than that of the other four basal media. The vertically inserted explants were found to yield a higher shoot regeneration frequency than that of horizontally inserted ones; the maximum difference of regenerating percentages between the two methods was 37.5%. In summary, TDZ was an efficient plant growth regulator for shoot induction. B5 medium and vertically inserted explants promoted shoot regeneration. We believe this highly efficient shoot regeneration system will provide foundation for the further transgenic studies in vegetable soybean.

选取84份经芜菁花叶病毒（TuMV）、霜霉病菌[Peronospora parasitica (Pers.) Fr.]、黑斑病菌[Al-ternaria brassicae (Berk) Sacc.]单抗鉴定后筛选出的自交系，于1992～1993年对其进行上述3种病害苗期人工诱发接种多抗性联合鉴定，获得21份三抗材料。经鉴定，确认为三抗抗源材料。探讨了多抗性联合鉴定的技术与方法。

1984～1989年在对不结球白菜种质源抗芜菁花叶病毒（TuMV）鉴定的基础上，利用杂种优势育种技术，以抗病矮脚黄雄性不育两用系为母本、抗病矮脚黄和雪克青自交系为父本，选育出综合性优良的矮抗二号和矮抗三号新品种。其特点：（1）丰产：生产试验平均产量分别达52.4和56.6t/hm2，比对照矮脚黄分别增产29.9%和40.2%；（2）抗病：两品种TuMV和霜霉病人工是鉴定病情指数比对照分别降低79.5%、98.7%和69.8%、88.0%；（3）优质；矮抗二号叶片重/叶柄重比对照提高17.0%，矮抗三号略低于对照，但其Ve、灰分、叶片和叶柄中可溶性固形物含量等主要营养成份均高于对照，且纤维素含量低；（4）商品性好：矮抗二号叶柄短且宽，色白。矮抗三号叶柄短且宽，色绿白，分别符合全国大部分喜食食白梗菜和青梗菜两大类型地区的消费习惯。