水稻不同籼粳分化品系主要农艺性状配合力的比较分析

分析比较了4个籼粳遗传分化程度不同的品系与8个常规籼稻品种配组杂交9个农艺性状的配合力效应。结果表明,一般配合力效应及特殊配合力效应与亲本的籼粳遗传分化程度没有明显的关系,4个不同遗传分化品系在9个性状上的一般配合力表现各异,总体上以偏籼品系G2417－1及偏粳品系G3005－4－1表现较好。122／G2417－1、4480／G2615、IR70／G3005－4－1、双桂35／G2615和明恢63／G2123等组合具有较高的单株产量特殊配合力。从2种配合力对杂种性状的影响程度看,在每穗实粒数、结实率、千粒重和单株产量等性状上,杂种主要受特殊配合力的作用,在抽穗期、株高、单株有效穗数、穗长、每穗总粒数等性状上,杂种主要受一般配合力的作用,但特殊配合力的作用亦不容忽视。抽穗期、单株有效穗数、每穗实粒数、结实率、单株产量等性状的超亲优势与两种配合力显著正相关,而多数性状的一般配合力与亲本表型效应值无显著的相关关系。     

两套水稻籼粳交DH群体的亲和性及其遗传分析

以两套水稻籼、 粳交DH群体为材料, 研究了籼、 粳程度及籼、 粳基因组的比例与亲和性 的关系, 结果 表明, 两套群体与籼、 粳测交F1小穗的育性与DH系的籼、 粳程度及基因组比例存在相 关, 但广亲和DH系(与籼和与粳测交F1小穗育性均大于70%)在籼、 粳程度及基因组比例 上的特异性不明显。 通过DH系与籼、 粳测交F1小穗育     

DH群体内株系对籼、粳亚种的亲和性

以窄叶青8号（ZYQ8）/京系17(JX17)的13个花培DH株系和培矮64／02428的11个花培DH株系为材料,分析了它们的籼粳分化及其对籼、粳亚种杂交的亲和性。结果表明,无论亲本是否具有广亲和性亲缘,两个DH群体均出现广亲和性良好的株系,且多数株系属籼粳中间类型。这说明虽然广亲和性是遗传的,但是籼粳基因的重组确实可以产生广     

生态条件对籼粳稻杂交F2代亚种特性分化与经济性状的影响

以籼粳稻杂交F2代群体(七山占/秋光)为供试材料,2010年分别在广东省与辽宁省同年种植,研究籼粳亚种属性和经济性状的分化规律以及两者之间的相互关系.结果表明,广东和辽宁2个生态地区群体,亚种特性呈相似正态分布,未出现偏分现象,说明在F2群体中遗传重组对群体的作用呈主导性.经济性状发生较显著的分化,穗数、千粒重、1次枝梗数及粒数辽宁地区显著高于广东,而产量、穗粒数及结实率呈现相应生态条件的偏向性,籼型及偏籼型在广东地区较高,粳型及偏粳型在辽宁地区较高,说明在籼粳交F2代中不同的籼粳类型存在较为显著的生态适应性,并且该结果在相关性分析也得了验证.此外,对进一步研究籼粳分化机制的相关问题进行了讨论.     

北方两系杂交粳稻及亲本的籼粳成分与株型和产量性状的关系

以北方两系杂交粳稻组合及其亲本为试验材料,采用程式指数法划分亲本和杂种的籼粳成分,研究其籼粳成分与杂种部分株型性状的关系。杂种在分蘖高峰期和成熟期的叶绿素含量与父本的程式指数呈显著正相关。杂种的剑叶叶长与母本的程式指数呈显著负相关,株高与母本籼稻成分呈显著负相关。在穗部性状与亲本籼粳成分分析中得出,穗长与父本和杂种的籼粳成分相关分析达显著负相关,穗数和穗粒数都与母本的籼粳成分呈显著负相关,穗粒数还与父母本籼粳成分之差绝对值呈显著负相关。叶绿素SPAD值与亲本的籼粳成分及其差值呈线性相关,存在临界极值。因此,北方粳型两系杂交水稻要获得良好的株型性状及产量杂种优势,父母本的籼粳成分要适度搭配。     

36个水稻骨干系的分子聚类及其遗传育种学意义 Ⅰ分子标记多态性与杂交亲和性关系的研究

对３６个水稻骨干系进行了ＲＦＬＰ（限制性内切酶长度多态性）分析，并对这些水稻材料的１６２个杂交组合育性进行了分组分类研究。杂种育性的遗传基础研究表明，亚种内杂交组合育性显著高于亚种间杂交组合育性。亚种间杂交不育性是由籼粳两个亚种间深刻的遗传分化引起的。广亲和性品种为亲本之一的杂交组合多数（７１．７％）具有正常的育性，ＲＦＬＰ分析表明，这些杂交组合的遗传基础特殊，其遗传距离大于典型的亚种内组合距离，而小于典型的亚种间遗传距离。广亲和性水稻种质的创建、改造和利用潜力是大的，广亲和基因作用及其与杂种优势表现有关的若干遗传育种学问题要协同一并去解决。     

籼粳中间型水稻光温敏核不育系浙科82S的选育

籼粳亚种间杂种优势利用是杂交水稻育种的重要研究方向,而选育利于实现籼粳亚种间优势利用的亲本材料是发挥籼粳亚种间杂种优势遗传潜力的重要材料基础。浙科82S是以粳型光温敏核不育系7001S为核不基因供体,以自育的籼粳中间型育种材料GS2066为父本,杂交选育的籼粳中间偏粳型光温敏核不育系。对浙科82S的育性、开花习性、自交和异交特性及配组优势等研究表明,浙科82S不育起点温度低,花时较早且集中,较高的异交率,且株型理想和具弱广亲和性,配组杂一代在穗粒数上具有较强的竞争优势,是籼粳亚种间优势利用的重要两系不育系。2015年通过浙江省农作物品种审定委员会审定。     

关于影响水稻籼粳交杂种F1结实率的初步研究

本文对两系稻籼粳交组合151S／华明921和151S／晚三及对照三系稻杂交组合汕优77分别进行剪叶和剪穗处理，并考察穗粒数、实粒数、结实率等性状作为基本资料，分析其部分库源关系对空秕粒形成的影响。结果表明：籼粳杂交稻的结实情况主要受库源关系的调节，且其受源的影响比较大，属于源限制型。因此生产上籼粳交杂水稻后期功能叶的保护比三系杂交水稻更为重要。其对结实率的提高有关键性作用。     

36个水稻骨干系的分子聚类及其遗传育种学意义：I分子标记多态性与杂交亲和

对３６个水稻骨干系进行了ＲＦＬＰ分析，并对这些水稻材料的１６２个杂交组合育性进行了分组分类研究。杂种育性的遗传基础研究表明，亚种内杂交组合育性显著高于亚种间杂交组合育性。亚种间杂交不育性是由籼粳两个亚种间深刻的遗传分化引起的。     

水稻亚种间、品种间杂交揭示杂草稻的起源和进化

杂草稻是在稻田或可耕地周边生长的类似杂草并兼有野生稻和栽培稻特性的稻属植株或群体。迄今对杂草稻的发生和进化尚有很多的争论和假说,本研究通过水稻亚种间和品种间的杂交试验以及亲本与杂交后代籼粳分化分子标记的遗传分析,对杂草稻起源和进化途径进行了探讨并提出了相应的防控策略。研究结果显示:亚种间和品种间特定亲本杂交组合(7个籼/粳,4个籼/籼)的后代中均可分离出类似杂草稻的植株,其频率为籼/粳>籼/籼;籼粳交或籼籼交F2-F4代群体中产生类似杂草稻植株的频率随世代增加呈现递增趋势(F2最低为1.26%,F4最高为15.35%),这与双亲的遗传背景有密切关系,即籼、粳亚种的遗传背景差距越大,其杂交组合后代中产生杂草稻的机率越高;籼/粳交组合安山稻/9311F3代分离群体中类似杂草稻的植株以籼型为主(占52.8%);韩国粳稻品种安山稻在籼粳组合中不论作母本或父本,杂交后代都易产生类似杂草稻单株,这可能与其籼粳组分遗传异质性较高有关;粳/粳组合后代中未鉴定出类似杂草稻的植株,预示粳稻品种间杂交可能不易产生杂草稻。本研究为杂草稻的防控和利用研究提供参考依据。     

Indica-Japonica differentiation of paddy rice and its relationship with heterosis

The Indica‐Japonica differentiation of three photoperiod‐sensitive and/or thermosensitive genetic male‐sterile rice (PGMS or TGMS, respectively) lines and 47 male parental lines from seven ecotypes were studied for their restriction fragment length polymorphism marker data to determine which ecotype crosses with the three PGMS and/or TGMS lines could lead to higher yield potential, and to estimate the relationship between the Indica‐Japonica differentiation of parents and heterosis in grain yield and its components. The results indicated that hybrids derived from ‘N422s’ and the early‐middle ripening Indica varieties from southern China, and hybrids between ‘Pei'ai64s’ and three Japonica ecotypes, including North‐eastern Japonica varieties, restoring lines of Japonica hybrid rice and north China Japonica varieties, showed the highest grain yields. There was less variation of yield among the F1s between ‘108s’ and the seven ecotypes than among the other F₁s. Highly significant positive correlations between heterosis of the F₁ yield and genetic distance of the parents were detected, although the correlation between F₁ yield performance and genetic distance did not reach a significant level. Considerable variation of correlation between heterosis and genetic distance was also detected in the Indica × Indica crosses and Indica × Japonica crosses. There was much higher correlation (r = 0.63) between the F₁ yield performance and the genetic distance of parents in the Indica × Indica crosses than in the others. It is proposed that a genetic distance of 0.4‐0.8 between the two parents of hybrid rice might be appropriate not only for F₁ performance, but also for heterosis.     

栽培稻的基因型差异程度和分类

本文利用来自一个籼/粳交(圭630/02428)的双单倍体(DH)系和由多种类型的籼、粳品种(系)组成的对照组,从分子水平上研究亚洲栽培稻的基因型差异。结果表明,栽培稻中存在两种主要的差异类型,即质的差异和量的差异。前者主要存在于籼、粳分化程度比较高的对照组中,85%以上的有关位点已经发生了籼或粳的分化趋向;后者主要存     

Identification of two types of differentiation in cultivated rice (Oryza sativa L.) detected by polymorphism of isozymes and hybrid sterility

Magnitudes of genetic variation within each of major varietal groups of cultivated rice were surveyed in terms of isozyme polymorphism and allelic differentiation of hybrid sterility loci, both of which are considered to have litt le selective value. Allelic differences for 20 isozyme loci were examined in a total of 337 accessions, including Indica and Japonica rices. Aus cultivars from India, Javanica cultivars and both landraces and cultivars from China. Eleven out of the 20 isozyme loci were polymorphic. The Aus cultivars contained more alleles per locus than others. The hybrid sterilities in the crosses among Chinese cultivars, Indica and Japonica cultivars were mainly controlled by locus S-5, whereas the hybrid sterilities of Aus cultivars, when they were crossed to Indica, Japonica or Javanica cultivars, were found to be controlled by allelic interaction at hybrid sterility loci S-5, S-7, S-9 and S-15. Also in terms of the number of alleles at S-5 and S-7, Aus cultivars contained more alleles than others. While the Aus group showed an extreme diversity for both hybrid sterility alleles and isozymes, modern cultivars from the south of YangZi River in China were classified into Indica type and those from the north were into Japonica, which were almost the same as those in Japan. On the basis of the measured polymorphism the Indica-Japonica differentiation was explained by founder effects, i.e., through selection and distribution of two original sources each with a unique set of markers. Contrastingly, the continuous and pronounced diversity in the Aus group was attributed to the absence of such a process. The intermediate groups in Yunnan province and Tai-hu Lake region of China are considered to be isolated from such founder effects, retaining an intermediate diversity in terms of isozymes and hybrid sterility genes. Since hybrid sterility hampers the exchange of genes between cultivars of different groups, the understanding of its genetic basis will be important in rice breeding, particularly in hybrid rice breeding. This revised version was published online in July 2006 with corrections to the Cover Date.     

Analysis of Vietnamese rice germplasm provides an insight into Japonica rice differentiation

Genetic differentiation among landraces of rice in northern Vietnam that lie in the centre of genetic diversity of Asian cultivated rice was analysed using DNA markers, and morphological and physiological traits to obtain an insight into the genetic differentiation of Asian rice. Principle coordinate analysis, based on nuclear RFLP data, divided Vietnamese rice varieties into three groups, designated A, B and C. Chloroplast DNA variation discriminated group A, which corresponded to the Indica rice varieties, from both groups B and C, which corresponded to the Japonica rice varieties. Physiological characteristics for Indica‐Japonica and tropical‐temperate Japonica discrimination suggested groups A and B consisted of typical Indica and Japonica varieties, respectively, while the characteristics of group C were distinct from those of the other two groups. This suggests that the genetic differences between groups B and C represent a new aspect of genetic variation that has not been previously reported in Japonica rice. Groups C and B corresponded with upland and lowland rice, respectively. Eight marker loci were associated with upland‐lowland differentiation in Japonica rice. Highlighted chromosomal regions might have been selected during the history of cultivation under different cultural conditions, and thus contain genes related to adaptation.     

Relationship between heterosis and genetic distance based on morphological traits and AFLP markers in pepper

Genetic diversity is considered as one of the criteria for the selection of parents for hybrid breeding. The present study was undertaken to evaluate genetic divergence among seven pepper cultivars and to assess the relationship between heterosis and parental genetic distance. Twenty‐one F₁ hybrids and seven parents were evaluated for 15 morphological characters in a greenhouse and in the field. The parents were examined for DNA polymorphisms using six amplified fragment length polymorphism (AFLP) primer combinations. Cluster analysis using two genetic distance measures grouped the seven parents differently. Mid‐parent and high‐parent heterosis was observed for most characters. Most hybrids outperformed the parental lines for fruit yield, earliness and plant height. Morphological and AFLP‐based distance measurements were efficient enough to allocate pepper genotypes into heterotic groups. The correlations of morphological distances with mid‐parent heterosis were significant for days to flowering and maturity, suggesting earliness can be predicted from morphological distances of parental lines. However, the correlations of AFLP‐measured genetic distances with mid‐ and high‐parent heterosis were non‐significant for all characters, except for fruit diameter, and proved to be of no predictive value.     

应用双单倍体克服籼粳交的不亲和性初探

通过对籼粳交Ｆ１体细胞愈伤组织的秋水仙素处理和四倍体花药培养，建成了水稻四倍体诱导及双单倍体分解系统。应用这一系统获得了４４个籼粳交组合的双单倍体及其自交４后代。对这些双单倍体及其后代的遗传分析表明，籼粳交育性可能受寡基因控制，双单倍体途径通过改变正常的世代交替过程，能部分克服籼粳交的不育性及倾籼或倾粳的偏态分离，并具有比Ｆ２更丰富的遗传多样性。在双单倍体一代群体中，育性正常的植株约占４０％，这是     

Increased regeneration from NaCl-tolerant callus in rice

Summary NaCl-tolerant calli were selected from two Japonica and two Indica rice (Oryza sativa L.) cultivars on basal media containing 6,000, 9,000, 12,000 or 15,000 ppm NaCl. Frequency of callus formation decreased with the increase of NaCl in the medium, especially in Indica. About half of the calli of Japonica cultivars selected on NaCl-ammended media survived 20,000 ppm NaCl but none of the Indica callus survived. In Japonica, more plants were regenerated from calli selected on all concentrations of NaCl media than from NaCl-free medium. Concentration of Cl^- in callus increased dramatically with increased NaCl content but peroxidase activity decreased.     

Genetic distance and its association with heterosis in peas

Summary The relationship between the genetic distance of parents and both the heterosis of F₁ hybrids and the variance of F₅ lines was investigated in 72 crosses of pea (Pisum sativum L.). The genetic distance between each pair of parents was estimated, using isozyme (GDi), morphological (GDm) or quantitative (GDq) markers and finally a combination of isozyme and morphological markers (GDi+m). GDm was poorly correlated with the other measures of genetic distance, which in turn were strongly correlated with each other. Genetic distance was moderately correlated with the level of heterosis for yield over midparent in the F₁ generation, with the highest correlation obtained from GDi+m. GD was not significantly correlated with heterosis for yield over the better or best parent but it was significantly correlated with all three measures of heterosis for pods per plant and hundred seed weight. There was no correlation between genetic distance and the level of heterosis for yield and total dry matter in the F₂ generation, but GDi, GDi+m and GDq were predictive for the level of inbreeding depression in grain yield and total dry matter. When parents were high in genetic distance, crosses produced highly transgressive segregants for basal branches per plant, hundred seed weight, harvest index and onset of flowering. Genetic distance between parents was thus a useful measure for predicting a portion of hybrid performance and also of the variance of derived inbred lines. It was concluded that when choosing parents for a cross, consideration should be given to their genetic distance as well as their overall adaptation and their yield. There is considerable potential for optimising choice of parental combinations in the development of improved pea cultivars.