【摘要】 大豆是短日照作物,到一定的临界光照才能开花。临界光照以下出苗到开花天数随光照缩短而减少。在贵阳(北纬26°35′)大豆生长期的自然光照下,经遮光缩短光照对国内有代表性大豆品种进行试验结果,其短光敏感性程度依次为南方夏大豆,北方夏大豆,南方春大豆和北方春大豆。而我省低纬高原大豆自海拔1000m以上短光敏感性随高度提高。经平均光周期近似值为14L+10D(自然光照),12L+12D,10L+14D,8L+16D等处理试验,结果后面两个处理的出苗到开花天数不再比12L+12D缩短。即加快发育要求的短光照有一定的限度。品种对缩短光照反应敏感程度还表现在花期缩短,从而提早成熟。结荚率提高,秋荚率减少,并增加百粒重。因而在生产实践中利用相对较长光照以延长营养生长期与开花期,之后在相对较短光照以提高结荚鼓粒的数量与质量极为有利更多还原

【Abstract】 Soybean belongs to the short day plant. The days from emergence of seedling to blossoming reduced as the light duration to be shortened below its critical illumination. Under the natual illumination conditions of Guiyang, photoperiodical experiment of representative varieties come from various areas of China was conducted. The result showed that the order of short photosensitivity is south summer soybean, north summer soybean, south spring soybean and north spring soybean. As for the local varieties originated from the area over 1000m of Guizhou plateau it showed that the altitute rising followed by the photoperiodical sensitvity increasing. In this study, the light duration treatments consisted of 14L+10D (L = light, D = dark), 12L + 12D, 10L + 14D and 8L + 16D. Experimental result showed that the days from emergence of seedling to blossoming of the 12L + 12D was shorter than that of the 14L + 10D (check, natural illumination) , but the days of te treatments 10L + 14D and 8L+16D were not reduced no more as compared with 12L + 12D. The short photosensitivity of the soybean varieties also showed in shortening the flowering period and then caused early ripening, high rate of bearing pods, blighted pods decreasing and grain weight increasing. It would be advantageous to elongate the period of vegetative growth and blossoming, and let the pod bearing and grain plumping in a condition of relatively shorter illuminatian cultural practice of the soybean.更多还原