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10 April 1994, Volume 8 Issue 2 Previous Issue    Next Issue
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研究报告
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研究报告

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Screening of Subspecies Differentiating RFLP Markers and Phylogenetic Analysis of Wide Compatibility Varieties in Oryza sativa Qian Huirong,Shen Bo,Lin Hongxuan,Lu Jun,Zhuang Jieyun,Zheng Kangle 1994, 8(2): 65-71 .  Abstract ( )   PDF (312KB) ( )   One hundred and sixty DNA clones were used to survey RFLPs among 21 wide compatibility varieties(WCVs) and 6 indica and japonica testers of Oryza sativa L. Sixty-eight clones distinguishing indica from japonica testers were detected. Based on ratios of shared fragments between WCVs and testers, 21 WCVs were divided into three groups: indica, japonica and intermediate. By further-screening among 15 indica and japonica varieties, 24 among 68 clones were found to be indica-japonica differentiating probes. They show same hybridization patterns within subspecies, but different patterns between the subspecies. RG358, G318 were confirmed to be indica specific clones, which showed null alleles in japonica varieties. A phylogenetic tree of 21 WCVs was constructed based on these 24 indica-Japonica differentiating probes and the significance of these probes in rice genetics and breeding practice was discussed.

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Morphological Observation on Embryos of Three Wild Rice Species in China Han Huizhen,Xu Xuebing 1994, 8(2): 73-78 .  Abstract ( )   PDF (316KB) ( )   The observations by dissecting microscopy and scanning electron microscopy to compare the embryos of the O. rufipogon, O. officinalis, O. meyeriana subsp. tuberculata showed that: 1) The mature embryonic surface features of O. rufipogon and O. officinalis were the same as cultivated rice. They differ with O. meyeriana subsp. tuberculata. 2)In the initial stage of organogenesis the embryonic surface feature of O. meyeriana subsp. tuberculata was similar to that of cultivated rice. Later on, embryo of cultivated rice formed ventral scale and lateral scales and coleoptile protrusion lacana; O. meyeriana subsp. tuberculata did not.

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The Relationship between Flowering Time of Rice and Weather Factors Ben Jianmin,Mo Huidong,Hui Dafeng 1994, 8(2): 79-84 .  Abstract ( )   PDF (242KB) ( )   The daily peak flowering time (FT) of 4 indica and 3 japonica varieties was measured under 6 seeding dates. The relationship between FT and main weather factors, including temperature (TP), relative humidity (RH), hours of sunshine (HS) from a.m. to I p.m., wind strength (WS) and days after heading (DH) was explored. The results are as follows: l) Significant difference existed in FT between indica and japonica rice. A large variance of FT was detected in each of 7 varieties, of which 46%-66% could be explained by the variation of weather factors. 2) The influence of weather factors upon FT differed widely in indica and japonica. In indica, the main factors were TP, HS and WS in order of importance, and no real effect of RH was found. In japonica, however, RH had the same effect as TP for FT, and HS was less important. WS showed very limited influence and varied with varieties. 3) Two regression formulas that could exclude the variation from the weather factors were given.

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Comparison of K-production Efficiency and Some Physiological Characteristics of Two Indica Rice Varieties Fu Jianrong,Zhan Changgen,Jiang Lina,Yu Tonghai 1994, 8(2): 85-90 .  Abstract ( )   PDF (301KB) ( )   Field trial and laboratory analysis were used to evaluate the differences between two indica rice varieties in K-production efficiency and related physiological features. The results indicated that K-production efficiency of the G88-293 variety was 28.8% higher than that of Zhe 852. The advantages in physiological features of the G88-293 possesses over Zhe 852 are as following: 1) Relatively smaller requirement for K in whole life period but higher percentage of K absorption and accumulation during early to middle growth stages; 2) Higher NP content of plants at early growth stages and higher K and K/N ratio in whole life; 3)Higher photosynthetic rate of flag leaves and higher storage of total sugar in stem and sheath at heading stage; 4) Prefered harvest index.

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Preliminary Studies on Characteristics of the Radiant Spectrum Causing the Formation of Insufficient Illumination Impairment during Rice Flowering-filling Period Li Lin,Zhang Gengsheng,Yao Yongkang 1994, 8(2): 91-96 .  Abstract ( )   PDF (335KB) ( )   Characteristics of radiant spectrum and reflection, transmission and absorption spectrums in rice colony at three weather condition, i. e. simulated cloudy, natural cloudy and sunny days during flowering-filling period, were analysed, to elucidate the reasons for impairment of rice production by light quality on cloudy days. The radiant energy with wavelength of 400-510 nm and 610-720 nmi. e. blue light and red light, greatly decreases and thus the radiant energy reflected by rice colony and transmitting through the colony increases in a greater amount, in the two wavelength range, which cause the radiant energy of the two parts of wavelength much less absorbed by rice colony.

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Yearly Discrepancy in Segregation Rate of Seed Setting in Nongken 58S/Nongken 58 F2 Population Cheng Shihua,Sun Zongxiu,Si Huamin 1994, 8(2): 97-101 .  Abstract ( )   PDF (148KB) ( )   Segregation of seed setting in the F2 population of a cross of Nongken 585, a japonica photoperiod-sensitive male sterile rice line, with Nongken 58, the original fertile parent of Nongken 585, was repeatedly observed under the natural conditions of Hangzhou (30°05'N) in the summers of 1989 and 1992, respectively. Distinctly yearly discrepancy in seed setting segregation in the F2 population was found. The rate of fertile plants was higher in 1989, when abnormally low temperature occurred during the summer, than in 1992. Smirnov test indicate that distribution of two observed data is different (P< 0.01 ). which is attributed to the effect of temperature on the expression of the photoperiod-sensitive male sterility. It is suggested that current methodology for genetic research on photo- or thermo-period sensitive male sterility in rice under natural conditions be unsuitable due to instability of temperature change. A new approach to study it is proposed.

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The Fecundity and Survival Simulation Modes of Experimental Population of Sogatella furcifera under Various Diet Condition Qin Houguo,Ye Zhengxiang,Li Hua 1994, 8(2): 102-106 .  Abstract ( )   PDF (287KB) ( )   The life parameters of Sogatella furcifera on rice at 5 growing stages (seedling, tillering, elongation, booting, heading) were studied. There were no significant differences among hatching rates of egg at 5 growing stages of rice plant. The survival rate of nymphs feeding on rice plant at elongation stage was the highest. Times of egg oviposition per female, egg number of a day per female, total egg number per female, daily survival rate of adult duration were the most when adults fed on rice plant at tillering stage. They were second in sequence when adults fed on rice plant at elongation stage. Based on experimental results of survival rate of nymph and adult, the experimental population simulation modes of survival rate of Sogatella furcifera were developed.

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Primary Study on Lipase Activity in Rice Seed Zhu Zhiwei,Lin Ronghui 1994, 8(2): 107-110 .  Abstract ( )   PDF (146KB) ( )   The rice lipase in japonica variety H129 was studied. The results showed that the lipase of rice distribute in the plumule and the scutum, not in the endosperm, It consists of several kinds of isoenzyme. It is different of the lipase active curve between the sterilized and the unsterilized rice seed, Opposite to the results of previous study, no lipase activity was found in the ungerminated rice seed and the dormancy rice bran.

研究简报

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Physiological Regulations on Fertility of Two-line Intersubspecies Rice Hybrids Lin Fei,Zhang Baohua,Hong Zhifan 1994, 8(2): 111-114 .  Abstract ( )   PDF (145KB) ( )   Two-line intersubspecies rice hybrids Yayou 2, Guangyou 6062 and Three-line hybrid rice Teyou 63 (Check) were used in the study, the results indicated that by the physiological regulations the relationships of sink-source-flow in two-line intersubspecies rice hybrids could be obviously improved, resulting in increasing assimilate for grain filling, decreasing empty and blighted grains, and raising 1000-grain weight. The large effect was found on fertility by amelioration of their plant space environment at the filling stage, while the potential of improving stem and sheath matter translocation to raise grain filling was smaller. Additionally, an inter-planting treatment show that higher fertility in the hybrids could be further expected by improving their pollination and fertilization.

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Effects of Blue Light on the Growth of Rice Seedlings Li Shaoshan,Pang Ruichi 1994, 8(2): 115-118 .  Abstract ( )   PDF (399KB) ( )   Effects of blue light on the growth of rice seedlings were studied. Blue light suppressed the height of rice seedlings with increase of irradiance, and the first leaves of seedlings treated with blue light unfolded earlier than those of seedlings treated with white light and dark. Blue light treatment decreased the area of the first leaf but increased its leaf angle. Treated by blue light, rice seedlings had well-developed root systems with increased dehydrogenase activity, and IAA oxidase activity in leaves also being increased. After being transplanted and grown under natural conditions, rice seedlings treated by blue light developed much more tillers than those treated by white light.

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Effect of External K+ Level on Salt Tolerance of Rice Seedlings Yan Bin,Dai Qiujie 1994, 8(2): 119-122 .  Abstract ( )   PDF (204KB) ( )   This study was conducted to determine effect of external K+ on rice salt tolerances under NaCl (0.5% or 86 mmol/L) stress. The rice seedlings were grown in the greenhouse for 15 days and then stressed with cultural solutions containing Na/K ratios of 5, 10, 50, 100, 369, and 0.5% KCl. The dry weight was decreased more under 0.5% KCl than under 0.5% NaCl. The addition of KCl to 0.5% NaCl solutions significantly minimized Na+ content in the plants, the total amount of (Na++K+) in the shoots, as well as the net rate of Na+ transport from root to shoot, and increased K+ in saline mediums significantly reduced membrane premeability of the roots and leaves, and enhanced plasmalemma ATPase activity of the roots. The results indicated that high external K+ level can improve salt tolerance of rice seedling. However, ameliorative effects of potassium were related with external Na/K ratio. Lower ratio aggravated the salinity injury. The optimum Na/K ratios which enhance s4lt tolerance were 10 and 50.

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Initiation, Development and Structure of Rice Nodular Structure Wang Honglong,Kang Yuqing,Zhang Cunjin 1994, 8(2): 123-125 .  Abstract ( )   PDF (213KB) ( )   Rhizobium pp. isolated from rice nodules induced rice root hair expanding, curling and branching. Rice nodule primordium was found 25 d after inoculation. Many small nodular structures were produced 30-40 d after inoculation. Most of these structures could not further develop and die. Different kinds of culture media affected the initiation and development of rice nodular structure, soil was the best. The cellular structure of rice nodules was similal to that of legume nodules. The infected cells were connected with vascular bundles by cortex. The infected cells were full of bacteria.

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The Correlation between Amylose Content and Grain Weight under Different Ripening Temperature Zhong Xuhua,Li Taigui 1994, 8(2): 126-128 .  Abstract ( )   PDF (172KB) ( )   The correlations between amylose content and 1000-grain weight in early season indica rice varieties were studied by both sowing-date experiments and controlled ripening temperature treatments. The Correlation coefficients in all the four non-waxy varieties, namely Hong 410, Zhong 83-49, D6033 and Hongtu 31, were found to be significantly positive and in the one waxy variety, Xiangfu 81-10, was very significantly negative. It suggested that the amylose content related with the filling degree of grains.