Studies On Purity Identification Of Hybrid Rice Seed Using The Thermo-energy Of Hotspring And Daylength-regulating Techniques

Rice is one of the most important staple foods in China.The planting area of hybrid rice counts for about 50 percent of all planting area. Hybrid rice seed with high quality, high purity is the foundation of gaining high yield, it is necessary to identify the purity of the seed before planting. In the paper,a new method via thermo-energy of Hotspring and daylength-regulating techniques to identify the seed purity was studied.The commercial seed od hybrid rice varieties with sensitivity to temperature and to photoperiod were used. The seed purity identification was carried out innediately after seed production and before marketing in the greenhouse in which air temperature and day-length was conditioned by using hotspring water and electricity lamp, at the same time,field planting identification and isozyme technology and Hainan planting method, were also used.In this study, we have been obtained followingresults:1 The effective temperature summation requried from sowing to heading when grown in the greenhouse is equivalent to the effective temperaturesummation in the field.The higher temperature in the greenhouse can shorten the growth period.2 It was more effective to advance their development when shorter daylength (about 10 hours per day) condition created at early growing stages(3-41eaf stage).3 The thermo-sensitive hybrid rice varieties growen in the greenhouse had fewer leaf number of the main culm and grew faster in the late stage. The growth period of the photoperiod-sensitive hybrid combinations were shorten under the shorter daylength condition.4 The greenhouse method was more accurate than Hainan planting method and isozyme analysis,for example,shanyou122, the correlation coefficient between results of the greenhousemethod identification and the field method identification was 0.9265, the average discrancy was 0.71%. The correlation coefficiention was 0.7901, the average discrepancy was 0.89%. The correlation coefficient between results of isozyme and the feld method is 0.698, The average discrepancy is 0.912%. Other varieties had the same trend. The results shiwed that the accuracy of greenhouse method was higher than Hainan planting method, and isozyme analysis.5 To the varieties with sensitivity to photoperiod. If it existes in the low temperature at night, under the shorter daylength condition, its absence of the shorter daylength is effective in the higher temprature. The growing stage can shorten easily. Studing the purity of the varieties with sensitivity to photoperiod was identified in the greenhouse. The identification result was more accurate than the varieties to temprature sensitive. It maybe study further.6 Because the greenhouse was in high temperature. The plant would feel ill easily, and affect its growth. Soit is important to improve the identification condition of greenhouse and accuracy.As a result, using greenhouse identification method, the seeds haversted in the autumn can be identified in the winter and the seeds haversted in the end of April or in the early of May can be identified in the late of May or in the early of June. As can provied immediately and useful references for the seed marketing in the earliest distribution eason. To sum up, Themo-energy of hotspring and daylength-regulating techniques was a simple,quicker and accurate method to identify the seed purity.