棉花柱头外露种质类型及其杂种一代的光温特性研究

The development characteristic of Cotton Germplasms with Stigma Showing(CGSS), which were cross-bred with Sea Island cotton and Upland cotton by our group were studied. The results showed that four of the 13 CGSS are sensitive to photoperiod; The sensitive stage is cotyledon stage. The critical day lengths that delay its budding are 12 hours for YS1, 12:20 hours for YS3 and YS8, 12:40 hours for YS4 respectively under summer high temperature in Nan Chang; While the critical day lengths leading to no budding are longer than those delaying, which are 13:40 hours for YS1, YS4 and YS8, and 15:40 hours for Ys3, respectively. According to the index of temperature and the effect of photoperiod, the CGSS could be divided into 4 types, as photoperiod-temperature sensitivity and early to middle maturity, photoperiod-temperature sensitivity and middle to late maturity, temperature sensitivity and early to middle maturity, temperature sensitivity and middle to late maturity; The basic vegetation periods (from seedling emergence till budding) of different types of CGSS varied from 14 to 30 days and changeable vegetation periods varied from 24 to 32 days. The factors of daylight and temperature can promote the maturation of F1 of CGSS. The sensitivity to photoperiod of F1 was primarily controlled by its parents CGSS. This will play vital role in breeding and hybrid seed producing through choosing high-yielding cultivars backcrossed more than twice with CGSS, with longer external stigma (more than 10mm) and higher crossing percentage (more than 95%).

研究棉供花柱头外露种质类型在不同地区、不同光温条件下的生长发育规律，探明其感光性、感温性和最短营养生长期的差异。根据种质的现蕾促进率、感温指数和最短营养生长日数三项指标进行光温反应型分类。并对几个有代表性的品种及杂交后代的光温特性进行探讨。为利用新种质进行超高产杂交育及配套技术提供理论依据。对棉花杂优利用具重大意义。