栽培稻种间近等基因系杂种育性研究

 为了研究亚洲栽培稻与非洲栽培稻种间杂种不育的遗传基础，以亚洲栽培稻品种WAB56-104为测验种与来自种间回交组合WAB56-104/CG14//WAB56-104///WAB56-104的14个种间近等基因系测交，对亲本及杂种的花粉及小穗育性研究表明，这14个近等基因系带有来自非洲栽培稻品种CG14的3个互不等位的配子消除位点和2个互不等位的花粉不育基因位点, 其中至少有2个配子消除位点未曾报道过。     

Grain Protein Content of Interspecific Progenies Derivedfrom the Cross of African Rice (Oryza glaberrima Steud.) and Asian Rice (Oryza sativa L.)

Abstract

The protein contents of the grain of 50 interspecific progenies developed from the cross between WAB56-104, an Oryza sativa variety, and CG 14, an Oryza glaberrima line, were investigated. In contrast to the higher protein content of O. glaberrima than O. sativa on the average, the protein content of CG 14 was always lower than that of WAB56-104. However, judging from the average of three seasons, 72% of the interspecific progenies had a higher protein content than the mid-parent and 50% of them had a higher protein content than WAB56-104. Although the actual values of protein content of the interspecific progenies were significantly different among the seasons, a highly significant correlation was always observed in protein content between any two of the three seasons. Protein content therefore was considered character of each interspecific progeny though it was also affected by environment. A significant correlation was not observed between paddy yield and protein content in any season; several interspecific progenies showed higher protein content and paddy yield than the mid-parents. A low paddy yield is likely to be associated with high protein content through physiological regulation without a genetic linkage between the two traits. However, the results suggest that the transgressive segregation of protein content observed in the interspecific progenies is attributed not to this physiological regulation but to a certain mechanism to concentrate protein in grains with a genetic background.     

同源四倍体水稻与非洲栽培稻杂交的后效性研究

利用亚洲栽培稻中的4份同源四倍体水稻(O.sativa,2n=4x=48)和相应的4份二倍体水稻(O.sativa,2n=2x=24)为母本,以4份非洲栽培稻(O.glaberrima,2n=2x=24)为花粉供体进行远缘杂交后,对其杂种后代的分离动态进行了研究.结果表明,不同倍性的普通栽培稻与非洲栽培稻之间杂交后代的结实率以二倍体普通栽培稻的较高.在配制的32个杂交组合中,其杂种第1代群体均表现出明显的营养生长优势.从群体的生长势来看,杂种第2代群体比杂种第1代群体要弱一些;在杂种第2代群体中,以同源四倍体水稻为母本的杂交组合的分离现象比以二倍体水稻为母本的杂交组合的分离现象更明显.在各杂交组合的第3代群体中,从植株的株叶形态和生育期来看,株系间的差异和株系内的变异依然很明显,变异频率更宽,变异种类更多.在普通栽培稻与非洲栽培稻的杂交组合中,育性变异、生长势变异、株叶形态变异、染色体变异和结实性变异等是较易发现的变异现象.     

栽培稻种间杂交改良云南粳稻品种研究

为引入非洲栽培稻的有利基因以丰富云南粳稻的遗传基础以达到培育高产、抗病、抗逆云南粳稻品种的目的,利用179个非洲栽培稻品种作母本与6个云南粳稻杂交,并用相应父本回交后形成F1、BC1F1、BC2F1、BC2F2群体,同时对滇粳优1号作轮回亲本的组合在BC2F1中每组合随机用5~10株回交至BC3F1。研究表明,F1及BC1F1的自交结实率为0,种间杂种不育是非洲栽培稻与亚洲栽培稻种间杂交最主要的生殖障碍;但回交至BC2F1自交结实率即达到7.9％, BC3F1的平均结实率为14.6％,在BC2F1选结实率在10％以上的植株自交1次,BC2F2的结实率即为42.8%,变幅15%~80%;表明杂种不育模式符合“单位点孢子体 配子体互作不育”。在BC2F2群体中,10.7％的组合的综合表现优于轮回亲本。大规模育种实践表明,通过两次回交,再自交2~3代,种间杂种不育的障碍基本可得到克服,并可引入非洲栽培稻的有利基因。     

栽培稻种间育性研究进展

杂种不育是影响亚洲栽培稻和非洲栽培稻之间基因交流的主要障碍,栽培稻种间杂交育性表现为数量性状位点控制的复杂遗传模式。杂种不育的遗传基础还需要深入研究。本文综述了育性方面的最新进展并对其实际应用的可能性进行探讨。     

Silicon Application in Cultivated Rices (Oryza sativa L and Oryza glaberrima Steud) Alleviates Iron Toxicity Symptoms Through the Reduction in Iron Concentration in the Leaf Tissue

Iron (Fe) toxicity is a constraint commonly encountered in waterlogged conditions. Under anaerobic conditions, reduced Fe is massively absorbed by plants and may induce the generation of reactive oxygen species. This oxidative stress is responsible for physiological perturbations, growth reduction and yield losses. Rice is known as a silicon (Si) accumulator. Although Si is not considered as essential, it is known to play a beneficial role in the resistance to biotic and abiotic stresses through diverse and sometimes unknown mechanisms. The aim of this study was to determine the alleviation of Fe toxicity through Si application in different genotypes. Therefore, cultivars of both cultivated rice species (Oryza sativa and Oryza glaberrima) and lines from a segregating population issued from a cross between IR64 (O. sativa subsp. indica) and Azucena (O. sativa subsp. japonica) were grown in hydroponics under standard or excessive Fe(II) conditions, with or without the addition of Si. The application of Si on Fe‐treated plants strongly alleviated Fe toxicity symptoms. The reduced Fe uptake by Si‐treated plants suggested that an avoidance mechanism would be involved in this alleviation. Moreover, an additive effect of the Si and Fe treatments on the absorption of other nutrients by plants was revealed. These promising results gave insights into the understanding of rice resistance mechanisms to Fe toxicity, opening new perspectives in its management through Si fertilization. Finally, plant response to Si application was greatly influenced by the genotype. Thus, selection of stronger Si‐accumulating varieties could also be of valuable interest in the improvement of rice resistance to Fe toxicity.     

栽培稻种间杂种不育性初步研究

栽培稻种间杂种不育是从非洲栽培稻向亚洲栽培稻转移有利基因及利用栽培稻种间杂种优势的最大生殖障碍,为克服栽培稻种间杂种不育障碍以充分、合理利用非洲栽培稻的有利基因,1999年至2001年在海南三亚用9个粳型亚洲栽培稻品种与2个非洲栽培稻品种杂交的17个F1组合,及与相应亚洲栽培稻回交的BC1F1为基本材料研究表明,F1所有组合均高度不育,回交一代花粉育性也很低,为0％—5．75％;在群体较大的BC1F1组合IRGC 102203/IRAT 216//IRAT 216中选育性最高的1株(32．10％)自交得76株BClF2,平均花粉育性为89．2％,之后种成76个BC1F3株系,每株系随机取1株自交至BClF5,BC1F5的花粉及小穗育性基本正常,再随机取23个株系与IRAT 216测交,BC2F1的花粉和小穗育性均表现为半不育。说明这23个株系均带有来自非洲栽培稻亲本IRGC 102203的不育基因,不育基因同时作用于雄配子和雌配子,杂种不育的遗传模式主要表现为“单位点孢子体一配子体互作不育”,经一代的选择和淘汰,育性基本恢复正常。大规模的回交转育育性基因及回交高世代QTL分析(AB—QTL)以更好地研究杂种不育的遗传规律及克服对策的研究工作正在进行中。     

栽培稻种间近等基因系杂种育性遗传及其基因定位

 用粳型亚洲栽培稻品种WAB56-104与来自种间回交组合WAB56-/104/CG14∥WAB56-104///WAB56-104的3个栽培稻种间近等基因系杂交、回交，对3个BC1F1群体的花粉及小穗育性遗传研究表明，育性遗传符合单位点孢子体-配子体互作模型，来自非洲栽培稻的不育基因在与相同位点的亚洲栽培稻等位基因互作时，导致携带亚洲栽培稻等位基因的雌雄配子败育，而形成花粉及小穗的半不育，但本研究的3个组合中，并未导致所有携带亚洲栽培稻等位基因的雌配子完全败育，其作用介于配子消除与花粉灭杀之间。用微卫星标记对这3个群体的育性基因定位表明，它们都位于第6染色体短臂末端，但WAB450-2、WAB450-8携带的不育位点与紧密连锁的微卫星标记RM190、RM133共分离，且很可能与S1等位，而WAB450-7的不育基因则与位于相邻区间的RM253呈松散连锁，可能与WAB450-2、WAB450-8的育性位点不同。     

Genetic analysis of resistance to green leafhopper, Nephotettix virescens (Distant), in three varieties of rice

The genetics of resistance to green leafhopper, Nephotettix virescens (Distant), in rice varieties ‘IR36’ and ‘Maddai Karuppan’ and breeding line ‘IR20965‐11‐3‐3’ was studied. The reactions of F₁ hybrids, F₂ populations and F₃ lines from the crosses of test varieties with the susceptible variety ‘TN1’ revealed that resistance in ‘IR36’ and ‘Maddai Karuppan’, is governed by single recessive genes while resistance in ‘IR20965‐11‐3‐3’ is controlled by a single dominant gene. Allele tests with the known genes for resistance to green leafhopper revealed that the recessive gene of ‘IR36’ is different from and inherited independently of Glh1, Glh2, Glh3, Glh4, Glh5, Glh8 and Glh9t. This gene is designated as glh10t. The recessive gene of ‘Maddai Karuppan’ and the dominant gene of ‘IR20965‐11‐3‐3’ are also non‐allelic to Glh1, Glh2, Glh3, Glh4, Glh5 and Glh8t. Thus, the dominant gene of IR20965‐11‐3‐3 is designated as Glh11t. The allelic relationships of the recessive gene of ‘Maddai Karuppan’ with glh8 and glh10t should be investigated.