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10 April 1993, Volume 7 Issue 2 Previous Issue    Next Issue
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研究报告
研究简报
综述与专论


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研究报告

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Ultrastructural Changes in Microsporogenesis and Pollen Development of Photoperiod Sensitive Genic Male-sterile Rice under Different Day Length Li Rongqian,Wang Jianbo,Wang Xiangming 1993, 7(2): 65-70 .  Abstract ( )   PDF (2763KB) ( )   Hubei Photoperiod Sensitive Genic Male-sterile Rice Nongken 58S was treated with different photopcriods in phytotron chambers of Koitotron S-153W at China National Rice Research Institute, Hangzhou. The 6-leaf old seedlings were exposed to short photoperiod of 10 h/d for 10d, and differentiation of the panicle proceeded under photoperiods of 13 and 14 h/d respectively. Panicle primordia were fixed and sectioned for TEM examination to investigate the role of different photoperiods on pollen sterility. Under 13 h/d pollen formation was quite normal, but under 14 h/d most pollen grains aborted at the late uninucleate stage. The altrastructural abnormalities include: aggregation of the ribosomes: gradual disintegration of the endoplasmic reticula, plastids, mitochondria and other organelles; absence of starch accumulation: increase of phagocytic vacuoles; thinning of the cytoplasm etc. and eventually abortion of the pollen grains. On the other hand, the tapetum remained intact and no disintegration of tapetal cells happened.

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Mutagenesis-induced Ultrastructural Changes in Suspension-cultured Rice Cells Hu Tianci,Gao Mingwei,Cheng Xiongying,Teng Junlin,Gao Qikang 1993, 7(2): 71-76 .  Abstract ( )   PDF (2136KB) ( )   The two-year old suspensions derived from the calli of japonica rice (CV. 02428) were normal in cell ultrastructures with well developed organs. However, the number of mitochondrion per cell decreased and starch grains in plastids and vacuoles in cytoplasm appeared 3 days after irradiation with 500R γ-rays. Cell structure changed dramatically with all cell organs disintegrated 6 to 12 days after the radiation indicating that the damage of cell ultrastructure caused by the irradiation is irreversible. Treatement with 5000R γ-rays brought about even greater damage to the suspensions, accelerating the disintegration of cell organs. The suspension cells treated with 1 mmol/L and 5 mmol/L of SA caused loss of growth ability. The suspension cells of 02428 showed a higher sensitivity to both physical and chemical mutagens as compared to the young panicle of the rice.

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Effects of Sucrose Concentration and Hormones on the Grain Development of Detached Rice Panicles in vitro Culture ReplaceChar1('spanTitle');ReplaceChar('spanTitle'); Liang Jiansheng,Cao Xianzu,Xu Sheng 1993, 7(2): 77-82 .  Abstract ( )   PDF (438KB) ( )   The influences of sucrose concentrations and different kinds of plant hormones on the solution and sucrose absorption and dry matter accumulation were investigated, with detached panicles of three different source-sink types of rice varieties cultured for 10 days in liquid culture. The results indicated that, with the some range of sucrose concentration, the volume of solution taken up by the grains increased with the increment of sucrose concentration, and decreased when the sucrose concentration was 320 mmol/L for Yayou 2 and Shanyou 63 and 160 mmol/L for Yanjing 2. Increasing the sucrose supply in the liquid culture from 20 to 320 mmol/L resulted in significant increase in the sucrose absorption by grains of all three rice varieties. When the sucrose concentration was between 20 and 160 mmol/L, the dry matter and starch accumulation of grains was stimulated by increasing sucrose supply, but when the sucrose concentration was higher, the dry matter and starch accumulation of grains of Shanyou 63 and Yanjing 2 was inhibited. The solution and sucrose uptake and dry matter and starch accumulation were regulated by plant hormones, but there were significant differences in the re sponses of rice varieties to hormones. It suggested that the sucrose and water moved to the grains be both dependently and independently, and sugar accumulation by grains be determined by grain sink strength as well as carbohydrate supply. The possible regulation of hormones on these processes was also discussed.

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Pigment Photobleach and Its Component Changes in Indica Varieties Leaves under High Light Fu Chunxia,Tan Xiuyun,Rui Renjie,Chen Yifeng,Zhong Weigong 1993, 7(2): 83-87 .  Abstract ( )   PDF (207KB) ( )   With high light, differences of pigment photobleach in 54 varieties observed under low CO2 and O2 (in water) showed that these varieties could be divided into 4 groups: Ⅰ. The resistant type which included 6 varieties with higher Chl and Car contents in photooxidation; Ⅱ. The sensitive type including 13 varieties with lower Chl and Car contents; Ⅲ. The specific type, having 3 varieties with higher Car but lower Chl contents: Ⅳ. The intermediate type. There were 32 varieties and their Chl and Car contents were intermediate. Under normal condition, the contents of Chl or Car and the ratio of Chl a/b or Car/Chl in the resistant type were lower than those in the sensitive one, and there were the linear correlations between the contents of Chl and Car as well as Chl a and Chl b in each type. However, treated by photooxidation the content of Chl or Car, the ratio of Chl a / b and SOD activity all decreased while only the ratio of Car/Chl rose in the four types. But these changes in the resistant type were less in comparison with the other types except the SOD activity. This indicated that the relative stability of pigment components characterized the resistance of indica rice to photooxidution which seemed to be the better function of SOD in scavenging the active oxygen.

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Effects of Rice Resistant Varieties on Population Growth of Brown Planthopper and Whitebacked Planthopper Yu Xiaoping,Wu Guorui,Tao Linyong,Wang Chengliang,Xu Qiqiang 1993, 7(2): 88-94 .  Abstract ( )   PDF (468KB) ( )   The life table and Morris-Watt mathematical model were used as the methods of comprehensive evaluation to analysis the resistance levels of 5 rice varieties to brown planthopper (BPH) Nilaparvata lugens Stal and whitebacked planthopper (WBPH) Sogatella furcifera Horvath. The results showed that variety IR36, Shanyou 6, Xieyou 10, Xiushui 620 and Bing 664 had significantly inhibiting effects on the population growth of BPH, but variety Xiushui 620, Bing 664 and Xieyou 10 were moderately resistant to WBPH. The results also indicated that the ovipositional stage of adults of both BPH and WBPH was the key stage on which the resistant varieties had the most adverse influence.

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The Mineral Nutrient Component and Characteristics of Color and White Brown Rice Qiu Lingcang,Pan Jun,Duan Binwu 1993, 7(2): 95-100 .  Abstract ( )   PDF (260KB) ( )   Eighteen elements of 252 unpolished rice samples which harvested from CNRRI experiment farm with the same ecological condition were analysed by ICP-AES method, and elements content and 12 elements nutrient supply demend rate (NSD) of color rice (33 red and 9 purple or black) were compared with 210 white rice. Results showed that either absolute element content of unpolished rice or NSD% polished rice can not reflect the real nutritive characteristics between color rice and white rice. Because people eat unpolished color rice and polished white rice. NSD comparison of unpolished color rice with polished white rice showed that Ba and V in color rice were lower than these in polished white rice, no difference in Sr, but other elements NSD were significantly higher. Within color rices, Mg, Ca, Ba, V and Fe of red rice were higher than purple rice. Thus, we must put more attention on the edible part of rice element and its bioavailability.

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Discussion on Genetics of Wide Compatibility by Pedigree Analysis Xiong Zhenmin,Min Shaokai,Zhu Xudong,Wang Jianlin,Cao Liyong 1993, 7(2): 101-104 .  Abstract ( )   PDF (294KB) ( )   The wide compatibility and indica-japonica differentiation of T984 and its seven pedigree parents i. e. C57, Jingyin 35, No. 300, Keqing 3, IR26, IR24, IR8 were tested. The result indicated that none of these seven pedigree parents showed wide compatibility. However the rice variety T984 which was originated from above seven varieties showed wide compatibility, when it was crossed with indica(Nanjing 11) and japonica (Akihikari and Zaoshajing) testers, their hybrids gave an almost normal fertility of 72.84%, 74.42% and 67.24%, respectively. In conclusion, the wide compatible lines can also be generated from hybridization between indica and japonica varieties both of which do not show wide compatibility.

研究简报

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The Heterosis and Combining Ability for the Days to Heading of the Sun Yiwei,Li Jiqing,Liu Yibo 1993, 7(2): 105-108 .  Abstract ( )   PDF (244KB) ( )   A partial diallel cross including 5 photosensitive genic male-sterile rice (PGMSR) lines as female parents and 10 wide compatibility (WC) varieties as male parents was made to study the heterosis and combining ability for the days to heading (DTH) of the F1 hybrids. The result showed that 5460S and Hengnong S-1 had better general combining ability (GCA), their F1 showed no heterosis; W6154S, W6184S and KS-9 had worse GCA, their F1 exhibited a significant positive heterobeltiosis, suggesting the difference in the DTH of F1 among parents and among combinations. The GCA of parents, especially the indica parents, played a more important role in controlling the DTH of F1s. The combining ability of a parent is related to its breeding relationship and the parent derived from the southeast Asia variety has better GCA. The relation between GCA and the photosensitivity gene was discussed.

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Response of Rice Seedling to Water Deficit at Different Leaf Age Wu Yongxiang,Huang Xiangxi,Zhao Guoliang,Chen Liugen,Chen Gonghan,Li Yongfeng 1993, 7(2): 109-112 .  Abstract ( )   PDF (243KB) ( )   The responses of different leaf age seedlings to water deficit for two cultivars (Shanyou 63 and Wuyujing 2) were studied in test pots. The whole process from growth stagnate, leaf curl to seedling death was observed. The results show that the sensitivity and tolerant ability to water deficit have obvious difference at different leaf stages of rice seedling. Besides extreme sensitiveness at bud stage, the sensitivity of seedling to water deficit enhances with leaf age increase, but tolerant ability is the most weak at stage of 2-3 leaf age of seedling. These response differences above-mentioned depened mainly on the size of leaf area of seedling, cultivar types and thickness of soil layer.

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Fertility Alteration and Flowering Habits of Photoperiod Sensitive Genic Male sterile Rice (PGMR) in the Cold Region Wu Changming,Cao Jingming,Fu Xiulin 1993, 7(2): 113-116 .  Abstract ( )   PDF (233KB) ( )   Fertility alteration characteristics and flowering habits of PGMR were studied under the local natural condition in Gongzhuling (43°21′N) and problem of using PGMR for hybrid rice breeding in the cold region were discussed. The critical photoperiod of fertility alteration of PGMR was 14.5-14.0 hours, but the local photoperiod could only meet the requirement of sterility of PGMR in the cold region over 38°N. Daily flowering time of PGMR was about 1 hours later and more dispersive than these of normal variety. It was low in the crossed pollination rate between PGMR and normal variety. Sterility of existing PGMR was unstable in the cold region. Fertility of PGMR was affected by temperature during differentiation stage of floret primodium.

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Analysis of Amino Acid Composition in Honeydew Excreted by Sogatella furcifera on Resistant and Susceptible Rice Plants Liu Guangjie,M. G. Ibabao,R. C. Saxena,B. O. Juliano 1993, 7(2): 117-119 .  Abstract ( )   PDF (127KB) ( )   Honeydew excreted by Sogatella furcifera on rice plants of selected varieties was collected and, total free amino acid (TFAA) and individual amino acids in honeydew were analyzed. Amounts of TFAA in honeydew from resistant varieties were significantly lower than from susceptible TN1. 19 amino acids were detected in honeydew excretion from both resistant and susceptible rice plants and predominant amino acids were glutamic acid, aspartic acid, valine and serine. Quantity of each amino acid in honeydew from resistant Rathu Heenati was significantly lower than that from TN1.

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Heizhenmi, A Black-kernel Rice Derived from Basmati 370 by Somaclonal Variation Zhao Chengzhang,Qi Xiufang,Yang Changdeng 1993, 7(2): 120-122 .  Abstract ( )   PDF (205KB) ( )   Heizhenmi, a black-kernel and good grain quality rice variety, was developed from Basmati 370 (White-kernel variety) by somaclonal variation. It has higher pigmentation (the pigment content is 2.6%) and vitamins (B1, E, C), micro-elements in grains compared to those of Basmati 370 and Yangxian Heimi (CK). The protein content is 13.29%. Especially, Se content in Heizhenmi is 1.5 times higher than that of Basmati 370, which acts as a anti-cancer element. The growth period duration is 125 days, and yield is 4950 kg/ha as second rice.

综述与专论

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Fertility Alterating Conditions and Ecological Adaptability of Photo-sensitive Genic Male-sterile Rice (in English) Zhang Ziguo,Zeng Hanlai,Yang Jing,Yuan Shengchao 1993, 7(2): 123-128 .  Abstract ( )   PDF (306KB) ( )   It has gradually become obvious that the fertility alteration of photo-sensitive genic male-sterile rice (PGMR) is simultaneously regulated by both photoperiod and temperature, and there exists a temperature range of photoperiod sensitivity, only within which is the pollen fertility alteration of PGMR regulated by photoperiod. And results suggested that the stage from secondary rachis-branch and spikelet primordia differentiation to pollen mother cell formation in the process of panicle development is the photoperiod sensitive stage of fertility alteration induced. During this stage, long-day conditions induce pollen sterility and short-day conditions induce its fertility under a certain temperature regime. The critical light length is 13.75-14.00 h/d and critical light intensity is 5-50 lux in Nongken 58S. The twilight can affect the inducement of fertility, too. The induction stage of thermo-sensitivity of fertility alteration are different between PGMR and thermosensitive male-sterile rice (TGMR). During this stage, lower temperature conditions cause pollen fertility and high temperaure conditions cause it sterility. The critical values vary as the gene transfered into different varieties. According to the results, the current sterile lines fall into 4 photo-thermo-types. The adaptabilities of them are different.