Effects of Nitrogen Application Amount during Various Periods on Yield of High Grade Hybrid Rapeseed

[Objective] The paper was to study the nitrogen application amount and nitrogen application model for high grade hybrid rapeseed （Brassica napus L.） to get high yield. [Method] With ＂Youyan 599＂ and ＂Sanbei 98＂ as materials, using quadratic regression orthogonal gyration combination design, the impact of nitrogen application amount during various periods on rapeseed yield was studied. [Result] The combinations of factors to obtain the highest yield index （2 898.211 kg / hm 2 ） of ＂Youyan 599＂ were as follows： living rape fertilizer 89.27 kg / hm 2 , opening fertilizer 120 kg / hm 2 , 12 th lunar month fertilizer 101.12 kg / hm 2 , total nitrogen application amount 310.39 kg / hm 2 . The proportions of living rape fertilizer, opening fertilizer and 12th lunar month fertilizer were 28.76%, 38.66% and 32.58%, respectively. The combinations of factors to obtain the highest yield index （2 870.14 kg/hm 2 ） of ＂Sanbei 98＂ were as follows： living rape fertilizer 120 kg / hm 2 , opening fertilizer 120 kg / hm 2 , 12 th lunar month fertilizer 37.55kg / hm 2 , total nitrogen application amount 277.55 kg / hm 2 . The proportions of living rape fertilizer, opening fertilizer and 12 th lunar month fertilizer were 43.24%, 43.24% and 13.53%, respectively. The combinations of factors to obtain the highest yield index of two combined varieties （2 813.82 kg/hm 2 ）were as follows： living rape fertilizer 120 kg/hm 2 , opening fertilizer 120 kg/hm 2 , 12 th lunar month fertilizer 76.23 kg/hm 2 , total nitrogen application amount 316.23 kg/hm 2 . The proportions of living rape fertilizer, opening fertilizer and 12 th lunar month fertilizer were 37.95% , 37.95% and 24.11% , respectively. [Conclusion] The paper provided theoretical basis for high yield cultivation of high grade hybridized rapeseed.

Effect of High Temperature on Outcrossing Characteristics at the Fertility Sensitive Period of Photo-thermo Sensitive Genic Male Sterile (PTGMS) Rice Lines

Four sterile lines （Peiai64S, Y58S, Guangzhan 63-2S and H638S） and the restoring line R527 were used as materials. Five temperature gradients （24, 27, 30, 33 and 36 ℃ in artificial climate chamber） and the natural temperature （as control） were treated to the four sterile lines for 6 d in the fertility sensitive period of heading to flowering stage, respectively, to study the effects of temperature on physiological biochemical characteristics of young panicles and outcrossing characteristics. The results showed that the percentages of exerted stigma of Peiai 64S and Y58S were the highest at 27 ℃, which were 86.81% and 86.06%, respectively, while the percentages of exerted stigma of Guangzhan 63-2S and H638S were the highest at 24 ℃, which were 76.24% and 81.76%, respectively; the stigma viability of Peiai 64S, Y58S, Guangzhan 63-2S and H638S were the best at 24 ℃, which were 1.96, 2.12, 1.74 and 1.94, respectively; the outcrossing rates of Peiai 64S, Guangzhan 63-2S and H638S were the highest at 24 ℃, which were 58.87%, 54.22% and 50.50%, respectively, while the outcrossing rate of Y58S was the highest at 27 ℃, which was 58.96%; and the contents of peroxidase （POD） of the four sterile lines increased significantly at 33 ℃ compared with the control, while the contents of malondialdehyde （MDA） and proline increased significantly at 36 ℃ compared with the control. There were differences in temperature sensitivity between the male sterile lines, and the 24 ℃ treatment during the sensitive period was the best for the fertility sensitive period of Peiai 64S, while 27 ℃ was the best temperature for Y58S, Gangzhan 63-2S and H638S.

The change of the cationic peroxidase in the leaves at the fertile transformation period in Nongken 58s

Nongken 58s is a type of photoperiod sensitivegenie male sterile rice which gives rice to malesterility when illuminated time is longer than13.75 h/d.The photoperiod sensitive stagesare from the differentiation of primary branchprimordum(Ⅱ)in young ears to fullness ofcontents of the pollen(Ⅶ).The changes ofactivity and isoenzymes in cation peroxidase atph0toperiod sensitive stages and the relation-ship between this enzyme and feritility of rice

Study on the Agroclimatic Division of Thermosensitive Genetic Male Sterility Rice Breeding

Using the meteorological data and geographical information during January-March（1961-2010） accumulated by 18 stations of Hainan,a suitability zoning map for thermo-sensitive genetic male sterility（TGMS） rice was made by GIS technology based on temperature indicators required by TGMS rice during fertility sensitive period and heading-flowering period,aiming to provide reasonable layout and scientific basis for sustainable development of TGMS rice in Hainan Island under the background of global warming.The results indicated that the suitable planting zones covered the south regions of Wuzhishan,Jianfengling and Diaoluoshan;subordinate suitable zones expanded northward to central parts of Wuzhishan,Dongfang,Changjiang,Qiongzhong and southern parts of Wanning;the other regions were unsuitable for breeding.