以光周期处理与分期播种试验综合鉴定大豆品种的光温反应

设置短日照(12 h)和长日照(16 h)两种光周期处理，并以春播模拟低温、夏播模拟高温条件，形成长日+低温、长日+高温、短日+低温、短日+高温4种光温组合。2007年对近年育成的10个北方春大豆Glycine max (L.) Merr.]品种(系)和18个黄淮海夏大豆品种(系)进行了光温反应特性鉴定。2008年对50份材料进行了光周期反应鉴定。结果表明，不论在低温(春播)还是高温(夏播)条件下，短日照均加快大豆的发育进程，导致开花提前；不论在长日照还是短日照条件下，高温均减少出苗至初花的日数。光周期和温度对大豆的发育存在明显的互作，随着温度的升高，短日照促进大豆发育的效应有所加强；随着日照的缩短，高温加快发育的作用也有所增大。供试大豆品种生态类型在光周期反应敏感度(PRS)、温度反应敏感度(TRS)及光温综合反应敏感度(PTCRS)等方面均存在显著差异。北方春大豆品种的上述3个指标均小于黄淮海夏大豆品种，但前者在不同光照条件下的温度反应敏感度差值和在不同温度条件下的光周期反应敏感度差值均较后者高，说明北方春大豆品种光温互作效应较强。

Identification of Photothermal Responses in Soybean by Integrating Photoperiod Treatments with Planting-Date Experiments

Soybean Glycine max (L.) Merr.] is a short-day crop that favors temperate weather. There have been a lot of studies on the responses to photoperiod, temperature or photothermal comprehensive regimes in soybean. However, little work has been conducted in the interactive effects of photoperiod and temperature on the development of soybean. To fully understand the photothermal responses of soybean and to identify the varietal variations in these traits, we designed two photoperiodic treatments of 12 h (short day or SD) and 16 h (long day or LD) integrated with two thermal conditions, high temperature (HT) (summer seeding in Beijing) and low temperature (LT) (spring seeding) in the current study. In 2007, the responses to the photoperiod, temperature, and photoperiod-temperature combinations of 10 spring sowing soybean varieties (lines) from the Northeast and 18 summer sowing varieties (lines) from Yellow-Huai-Hai River Valleys of China were identified in 4 photothermal regimes (LD+LT, LD+HT, SD+LT, SD+HT). In 2008, 50 varieties (lines) were used to test the photoperiodic responses. The results showed that SD promoted the developmental rate of soybean regardless of the temperature conditions; HT shortened the number of the days from emergence to flowering no matter whether the photoperiod was long or short. There was significant interaction between temperature and photoperiod from emergence to flowering. With the increase of temperature, the promotive effect of SD on developmental rate of soybean was enhanced, and the HT hastening effect was strengthened by SD as well. The apparent differences in photoperiod response sensitivity (PRS), temperature response sensitivity (TRS) and photothermal comprehensive response sensitivity (PTCRS) between ecotypes were observed. The above three indices of spring sowing soybean varieties from the Northeast were all lower than those of summer sowing varieties from Yellow-Huai-Hai River Valleys. However, the differences between TRS values under the two photoperiod treatments and that between PRS values under the two temperature conditions in spring sowing soybean varieties from the Northeast were both larger than those in summer sowing varieties from the Valleys, and it indicated that there was higher photoperiod × temperature interaction in the spring sowing varieties. The relationship between photothermal responses of soybean varieties and their ecological adaptability was discussed, and it proposed that, in breeding program, emphasis should be paid not only on the identification of responses of soybean varieties to the individual photoperiod or temperature factor but also on the photothermal interaction.