春播和秋播对南方春大豆种子活力的影响

试验采用春播（４月４日）和秋播（７月３０日）两种播期法，研究春播种子活力低，秋播种子活力高的生理生化原因，结果表明，种子发芽率，发芽指数，电导率，过氧化物酶活性和真菌侵染率，这些反映种子活力的生理指标，秋播种子均优于春播种子，此外，秋播种了表皮结构较春播种子致密，种子表面小孔数目少而小，这可能也是秋播种子活力高的原因之一。

Effects of Plantings in Spring and Fall on the Vigor of Spring Soybean Seed in Southern Region

In order to find out the cause of the lower vigor of the spring planted soybean seed and the higher vigor of the fall planted soybean seed, several physiological, biochemical and even biological properties concerning the vigor of the soybean seed were studied. Two cultivars were planted in spring(4/4) and fall(7/30) and the results showed that the germination percent age,germination energy, germination index, electric conductivity, and the POD activity of the seed of the fall planted soybean were superior to those of the seed of the spring planted soybean. The spring planted soybean seed was also less infected by seed-borne pathogenic diseases. Be sides, the seed coat of the fall planted soybean seed was more compact than that of the spring planted seed, with less and smaller holes. Perhaps this might be one of the reasons for the higher vigor of the fall planted seed.