Distribution of the Classification Traits in the F2 Progeny of Two Crosses of indica/japonica in Rice (Oryza sativa)

Comparison of seed setting rate, plant height and Cheng′s morphological traits were made between the F2 progeny of indica japonica hybrids, 02428/Pei′ai 64 and Taichung 65/Teqing. There existed resemblance normal distribution in plant height, and the distribution had no relationship with the seed setting rate and plant height in F1 progeny, suggesting that there were no gametic selection for the plant height in the F2 progeny of indica japonica hybrids. An average seed setting rate of the F2 was equal to the F1 populations in the recombination of 02428/Pei′ai 64 in which there was an excellent cross compatibility, but the remarkable increase in the seed setting rate from the F1 to F2 in Taichung 65/Teqing, indicating that gametic selection only took place in the indica japonica crosses with low cross compatibility while null or little in the hybrids with high compatibility. There were many intermediate types among the leaf pubescence, color of hull at heading, and length of the first and second panicle internode, and these Cheng′s morphological traits was distributed normally; there were also a little intermediate types in hull hairness and phenol reaction with bi peak distribution; while length to width ratio of grain was inclined to the japonica types obviously showing a skewed distribution in the F2 population. Although Cheng′s morphological traits in F2 populations had inconsistent distribution types, Cheng′s morphological traits index showed normal distribution, which suggested that intermediate types, i.e. indicalinous or japonicalinous, were primary in F2 population.     

Traits Related to Chilling-Induced Photoinhibition in Leaves of indica and japonica Rice （Oryza sativa）

Physiological indices related to PS II photochemical efficiency (Fv/Fm) and membrane lipid peroxidation were measured in leaves of indica rice cv Shanyou 63 and japonica rice 9516 at different temperatures and light intensities for four days. No obvious changes in Fv/Fm and MDA were observed in both indica and japonica rice at moderate temperature and medium PFD, implying neither photoinhibition nor photooxidation happened in these cases. In indica rice either at medium temperature with higher PFD or at lower temperature with medium PFD Fv/Fm dropped obviously with no changes in MDA contents, and photoinhibition appeared while photooxidation did not occur. However, D1 protein, Fv/Fm, (A Z)/(A Z V), and SOD activities dropped, and O2 - production and MDA content increased accordingly, as well as both photoinhibition and photooxidation appeared in two rice varieties at lower temperature and higher PFD. Experiment with inhibitors at lower temperature and higher PFD showed that as compared with japonica rice the decrements appeared in D1 protein contents, SOD activities, and (A Z)/(A Z V) ratios, the xanthophyll cycle and non-photochemical quench (qN) were inhibited in a more degree, as well as increments of MDA content were greater, thus exhibiting more distinct photoinhibition and photooxidation in indica rice. It is suggested that Fv/Fm and membrane lipid peroxidation product-MDA were the key indices to predict and diagnose photooxidation.     

Phenotypic Expression of Whitebacked Planthopper Resistance in the Newly Established japonica ／ indica Doubled Haploid Rice Population

A new doubled haploid (DH) rice population was established from a cross between WBPH-resistant japonica Chunjiang 06 (C J-06) and susceptible indica TN1. Sucking inhibitory and ovicidal resistance of the DH rice lines were evaluated on the basis of non-preference response of WBPH immigrants and honeydew excretion by WBPH females, and appearance of watery lesions in the necrotic discoloration of leaf sheaths ovipositied by WBPH,respectively. Both the major gene resistance to WBPH, sucking inhibitory and ovicidal resistance, showed 1 (resistant): 1 (susceptible) segregation ratio in the DH population. Relative density of WBPH populations and damage scores in the DH population indicated combined functions of both the major resistance genes as well as QTLs affecting the host plant response to WBPH infestations. Thus, the newly developed CJ-06/-I-N1 DH population could be a useful material to analyze major genes and QTLs for WBPH resistance in japonica rice.     

Transgenic Expression of the Recombinant Phytase in Rice （Oryza sativa）

In many plants, phytic acid (phytate, 1, 2, 3, 4, 5, 6-hexakisphosphate) is one of the main storage forms of phosphate. About 80% of phosphorus (P) in cereal plants, including rice is stored as phytic acid [1-2]. P in phytic acid can’t be utilized by monogastric animals including human, while it was estimated that only 1/3 of the total P in most of the vegetal feedstuff could be efficiently utilized by the livestock. Therefore, for animal feed with P supplementation is expected to meet the d…     

Correlation Between Parents and F1 and Combining Ability of Parents on Seed Dormancy in indica Rice （Oryza sativa）

Dormancy indices of hulled and dehulled seeds were investigated by using 19 cytoplasmic male sterile (CMS) lines, 9 restorer lines and their 109 F1 hybrids of indica hybrid rice. The seeds of each F1 and the parents were harvested on 35 days after flowering. Combining ability was analyzed in 25 combinations made by 5 CMS lines and 5 restorer lines (North Carolina II mating design). The seed dormancy index of F1 was positively and highly significantly correlated with those of their parents and mid-parent value. Out of the 109 combinations, 82 combinations showed mid-parent heterosis, and 43 heterobeltiosis. Seed dormancy indices of F1s and their parents declined dramatically in dehulled seeds compared with hulled seeds, indicating that the hull played an important role in seed dormancy. However, the trends were similar in hulled seeds and dehulled seeds in terms of relationships between the seed dormancy indicices in F1 and their parents. The influence of hull on seed dormancy mainly depended on F1 genotype, not on the hull from maternal parent. The variances of general combining ability (GCA) in female and male parents occupied 59.2% and 31.1% of total variance, respectively. The variance of specific combining ability (SCA) in combinations occupied 9.7% of total variance, indicating that gene additive effects were principal. Among the 5 CMS lines, II112A had the highest GCA effect for seed dormancy, followed by D62A. Among the 5 restorer lines, IR112 had the highest GCA effect for seed dormancy, followed by 2786. These lines are elite parental materials for breeding F1 hybrid rice with stronger seed dormancy.     

Physiological Characterization of Zn-efficient Rice （Oryza sativa） Genotype at Different Zn^2＋ Levels

Physiological characteristics of rice at different Zn2+ levels[pZn2+＞11.5, 11.3, 11.0, 10.6, 10. 3, 9.7] were studied with the Zn-efficient rice cultivars IR34, IR36, IR8192, and Zn-inefficient rice cultivars IR26, Ce 64-7, Biyuzaonuo,which grew in chelator-buffered nutrient solution. There were significant differences in tolerance to zinc deficiency among different rice genotypes. Obvious effects of low zinc activity on the physiological characteristic of rice seedlings were noted.There were significant differences in chlorophyll content, photosynthesis rate, MDA concentration in rice leaf, and H+ excretion of root. As pZn2+ decreased, chlorophyll content and photosynthesis rate decreased at a slower pace in Zn-efficient cultivars compared to Zn-inefficient ones, MDA concentration increased slower while H+ excretion of root increased faster in Zn-efficient cultivars than those in Zn-inefficient ones. It was suggested that the above indications could be used as indexes to Zn-efficiency of rice.     

Molecular Cloning and Characterization of Citrate Synthase Gene in Rice （ Oryza sativa）

The full-length OsCS encoding citrate synthase was isolated from rice （Oryza sativa L. subsp, japonica）, OsCS is 1477-bp long and encodes a 474 amino acid polypeptide, Its putative protein sequence is highly identical to Daucus carota, Nicotiana tabacum Beta vulgaris subsp., Arabidopsis thaliana, and Citrus junos （〉70%）. The deduced amino-terminal sequence of OsCS showes characteristics of mitochondrial targeting signal. Southern blot analysis using ORF of the OsCS as the probe indicated that this gene exists in multiple copies in rice genome. The band with predicated size of 82 kD was detected by Western blot after being induced by 0,4 mmol/L IPTG.     

Grain Quality and Genetic Analysis of Hybrids Derived from Different Ecological Types in Japonica Rice （Oryza sativa）

The performance and inheritance of 7 quality traits were studied using F2 rice grain derived from 8×8 diallel crossing made by employing 8 parents of different ecological japonica rice types. Differences in each trait among 8 parents were not obvious, but in F2 generation, transgressive phenomena were found in all the traits studied, indicating that the genes controlling these traits among parents were segregated. The inheritance of grain width, grain weight, chalkiness score (CS), gelatinization temperature (GT) and gel consistency (GC) were suitable to additive-dominant model, and dominant effect contributed mainly for the 5 traits. The inheritance of grain length (GL) and amylose content (AC) did not fit into additive-dominant model, existing epistatic interactions. Dominant genes for grain width and grain weight had the efficiency of decreasing effect, and dominant genes for CS, GT and GC had the efficiency of enhancing effect. Koshihikari contained more recessive genes for gelatinization temperature than other varieties. Zhendao 88 had more dominant genes in grain width and grain weight than other varieties. Xiushui 04 possessed more dominant genes for GL and GC, and more recessive genes for CS than other varieties.     

两个籼粳交杂种F2几个重要性状的分布

比较了02428/培矮64和台中65/特青两个不同的籼粳交组合F2结实率、株高和几个程氏分类性状的分布。结果表明：（1）两个组合的株高呈现相似的正态分布,不受其F1结实率和株高的影响,说明F2株高不存在配子选择问题;在杂交亲和性较好的02428/培矮64中,F2的平均结实率与其F1的结实率几乎相等,而台中65/特青结实率则表现为由F1到F2增加的趋势,说明配子选择在亲和性较好的杂种中很少或不存在,而在亲和性相对较差的组合中存在。（2）在程氏分类性状的分布中,叶毛、抽穗时稃色和第１~２穗轴节长等存在大量的中间类型,表现明显的正态分布,稃毛和酚反应虽呈双峰分布,但仍然存在少量的中间类型,而谷粒长宽比则表现极端的偏斜分布,明显地偏向粳型。虽然各分类性状表现不同的分布类型,但程氏分类指数表现出正态分布,即偏籼偏粳的中间型占绝大多数。关键词     

Traits Related to Chilling-Induced Photoinhibition in Leaves of indica and japonica Rice (Oryza sativa)

Physiological indices related to PS Ⅱ photochemical efficiency (Fv/Fm) and membrane lipid peroxidation were measured in leaves of indica rice cv Shanyou 63 and japonica rice 9516 at different temperatures and light intensities for four days. No obvious changes in Fv/Fm and MDA were observed in both indica and japonica rice at moderate temperature and medium PFD,implying neither photoinhibition nor photooxidation happened in these cases. In indica rice either at medium temperature with higher PFD or at lower temperature with medium PFD Fv/Fm dropped obviously with no changes in MDA contents, and photoinhibition appeared while photooxidation did not occur. However, D1 protein, Fv/Fm, (A Z)/(A Z V), and SOD activities dropped, and O2 -. production and MDA content increased accordingly, as well as both photoinhibition and photooxidation appeared in two rice varieties at lower temperature and higher PFD. Experiment with inhibitors at lower temperature and higher PFD showed that as compared with japonica rice the decrements appeared in D1 protein contents, SOD activities, and (A Z)/(A Z V) ratios, the xanthophyll cycle and non-photochemical quench (qN) were inhibited in a more degree, as well as increments of MDA content were greater, thus exhibiting more distinct photoinhibition and photooxidation in indica rice. It is suggested that Fv/Fm and membrane lipid peroxidation product-MDA were the key indices to predict and diagnose photooxidation.     

利用SSR标记和表型性状聚类分析食味优良粳稻多样性

 用SSR分子标记、食味性状、农艺性状3种数据对来自国内外不同地域的食味表现优良的常规粳稻品种（系）进行了多样性分析。72对SSR引物在60份供试材料中检测到290个等位基因变异,以第5染色体上平均等位基因数目最多。大部分食味优良粳稻材料之间的遗传相似性较高,遗传相似系数范围为0600~0924,检测的标记是以3~4个等位基因为主的SSR引物位点。利用SSR标记检测等位基因的材料分群结果表现出一定程度的地域性,江苏省内大多材料可聚为一类,而其他少数及北方粳稻材料多与国外食味优异粳稻品种亲缘关系较近,与其系谱分析结果基本一致。以食味鉴定表型性状为依据,部分产地来源不同而食味优良的材料明显聚为一类,表明遗传基础是决定其食味的主要因素。农艺性状表现与材料来源有一致性,而与食味优良的关系有待进一步明确。     

不同年份水稻产量性状的QTL分析

分别于2005年和2006年利用热研2号（粳稻）和密阳23（籼稻）为亲本构建的含111个家系的F6和F7重组自交系群体,对单株穗数、每穗颖花数、每穗实粒数、结实率、千粒重和单株产量6个性状进行了QTL分析。两年共检测到分布于7条染色体上的19个QTL,其中2005年检测到10个,2006年检测到14个,两年相同的QTL 5个。大多数性状之间具有显著的表型相关性,相关性较强的性状之间具有较多共同或紧密连锁的QTL。检测到3个控制产量性状的QTL区域存在一因多效或紧密连锁,其中第8染色体上RM5556-RM331区域两年同时检测到控制每穗颖花数、每穗实粒数以及单株产量的QTL。这些QTL为通过分子标记辅助选择提高水稻产量提供了有用信息。     

杂交水稻种子穗萌遗传效应的研究

 以穗萌抗性水平不一的6个不育系和7个恢复系为亲本材料，采用不完全双列杂交的试验设计，并运用包括胚乳、细胞质和母体植株三套遗传体系的种子遗传模型及估算遗传方差分量和预测遗传效应值的统计分析方法，对杂交水稻种子穗萌特性的遗传效应进行了研究。结果表明，杂交水稻种子的穗发芽率同时受种子直接加性、种子直接显性和母体加性效应的影响，且以种子直接效应为主，不受细胞质和母体显性效应的影响。在选择育种中，田间穗上发芽率以单粒选为好。而穗萌指数同时受制于种子直接遗传效应、母体效应和细胞质效应，但母体植株中只测到显著的母体加性效应。     

粳稻叶片茸毛和谷壳稃毛的分布特征及毛数的遗传分析

在光学显微镜下观察了粳稻叶片茸毛在叶面上的分布特征和谷壳稃毛在谷壳上的分布特征。调查了粳稻3个杂交组合的P1、P2、F1、B1（F1/P1)、B2(F1/P2) 和F2共6个世代的叶片茸毛数和谷壳稃毛数,运用主基因+多基因混合遗传模型6个世代联合分析的方法,对这两个性状进行了遗传分析。结果发现,叶片茸毛有规律地分布在叶面的暗绿条带和淡绿条带的交界线上,形状是基部膨大,顶端细小;谷壳稃毛无规律地分布在整个谷壳上,长短不一。在泗稻10号A/武育粳3号R与武育粳3号A/泗稻10号R正反交组合中叶片茸毛数均受1对加性主基因+加性 显性多基因共同控制,在六盐189A/HR 122组合中叶片茸毛数受1对加性 显性主基因+加性 显性多基因共同控制; 在3个杂交组合中谷壳稃毛数均受1对加性主基因+加性 显性多基因共同控制;叶片茸毛数和谷壳稃毛数都以主基因遗传为主。     

Distribution Characterization of Leaf and Hull Pubescences and Genetic Analysis of Their Numbers in japonica Rice (Oryza sativa)

Distributions of pubescences on leaf blade and hull in japonica rice were observed under an optical microscope. Numbers of leaf and hull pubescences in P1, P2, F1, B1, B2 and F2 generations were investigated in three combinations of japonica rice (Sidao 10A/Wuyujing 3R, Wuyujing 3A/Sidao 10R and Liuyan 189A/HR-122), and genetic analysis for these two traits were conducted by using the joint analysis method of P1, P2, F1, B2, B2 and F2 generations with the mixed major gene plus polygene inheritance models. Leaf pubescences characterized by swollen base and fine tip distributed regularly on the boundary between dark green stripe and light green stripe of leaf blade. Hull pubescences with various lengths distributed irregularly on the whole hull. Numbers of leaf pubescences in the reciprocal combinations of Sidao 10A/Wuyujing 3R and Wuyujing 3A/Sidao 10R and numbers of hull pubescences in all the three combinations were controlled by one pair of additive major genes plus additive-dominant polygenes. In the combination of Liuyan 189A/HR-122, number of leaf pubescences was controlled by one pair of additive-dominant major genes plus additive-dominant polygenes. Both numbers of leaf and hull pubescences were mainly governed by major genes.     

几种植物生长调节剂对水稻籼粳交F_1代增产效应的研究

以籼粳杂交组合亚优２号为供试材料，采用盆钵与大田试验相结合，研究了１２种植物生长调节剂对亚优２号的农艺性状及产量的影响。研究结果表明，适时适量地使用植物生长调节剂能改善籼粳交Ｆ１的农艺性状，提高结实率。