Relationship of Parental Indica-Japonica Indexes with Yield and Grain Quality Traits of Japonica Hybrid Rice in Northern China

Taking the main parents （10 male sterile lines and 10 restorer lines） and their 100 combinations of japonica hybrid rice in northern China as materials, the relationships of parental indica-japonica indexes determined by the methods of the Cheng’s index as well as simple sequence repeat （SSR） markers with yield and grain quality traits of hybrid rice were studied. For the parents, the Cheng’s index （Chi） ranged from 13.5 to 19.3 and the indica index in SSR markers （ADi） were from 0.12 to 0.38. The classification of parents by Chi was not completely consistent with that by ADi. The Chi of male parent was more closely related to hybrid traits than that of female parent, as contrasted to ADi. At the same time, the difference between parents （PD） in Chi was more closely related to hybrid traits than that in ADi. The indica-japonica indexes of parents and their difference between parents appeared quadratic relationship to hybrid traits with the critical extremum. The directions of the correlation of indica-japonica indexes of parents and their differences with hybrid yield traits were on the opposition to those with hybrid grain quality traits. Therefore, the female parent should match the male parent moderately in indica-japonica index to obtain the optimum of hybrid traits, high yield as well as good quality.

Relationships of Panicle Type Index with Subspecies Characteristics and Yield Traits in Filial Generation of Crosses between Indica and Japonica Rice

Two recombinant inbred line （RIL） populations, one derived from a cross between Zhongyouzao 8 （indica） and Toyonishiki （japonica） and the other from a cross between Qishanzhan （indica） and Akihikari （japonica）, were grown in Liaoning and Sichuan Provinces, China, to study the panicle type index （PTI, the ratio of a number of node position on panicle axis where the secondary branch with the most numerous secondary branch grains is located to the number of primary branches） and its relationships with subspecies characteristics and yield traits. With continuous distribution of PTI and numerous of lines with different PTIs in the progenies, indica-japonica hybridization could be a method for breeding cultivars with ideal panicle type. PTI was significantly influenced by environments, with a significant decrease from Liaoning to Sichuan A significantly negative correlation was found between PTI and most of subspecies characteristics. PTI varied remarkably with different subspecies types. As a whole, it showed a trend of indica （H）〉indicalinous （H＇）〉japonicalinous （K＇）〉japonica （K） However, it is not appropriate to regard PTI as a parameter for subspecies classification in rice because it was recombined in the filial generations of cross between indica and japonica rice. The negative correlations were found between PTI and most of panicle characteristics, as well as yield-related traits. Based on PTI, most of lines from the two populations were middle dominant panicle type （the number of grains on the secondary branch is numerous in middle position of the panicle） and lower dominant panicle type （the number of grains on the secondary branch is numerous in lower position of the panicle and becomes less towards the top of panicle） with significant yield advantages.

Analysis of Indica-Japonica Differentiation in Rice Parents and Derived Lines Using ILP Markers

Revealing the indica-japonica differentiation in parents of hybridization between indica and japonica rice and their derived lines can provide theoretical and practical bases for the breeding of practical inter-subspecific hybrid rice. Using subspeciesspecific molecular markers ILP （intron length polymorphism） and Cheng＇s index, the indica-japonica differentiation was analyzed with special materials including 18 indica-japonica hybrid parents and 39 derived lines, which accumulated different wide compatibility and restoring genes by convergent cross method in 21 years spanning four breeding phases. The indica-japonica differentiation was detected on all tested loci in 57 materials. Among the 18 parental lines, 4 were japonica type, 5 japonicaclinous type, 8 indicaclinous type and one indica type. The japonica proportion indexes in indica restorer lines Minghui 63 and 9308 were 12.50 and 33.33 %, respectively, while that in japonica restorer line C418 was only 31.25%. Among the 39 derived lines from indica-japonica hybridization, one was japonica type, 11 japonicaclinous type, 20 indicaclinous type and 7 indica type. The japonica proportion index in Minghui 502 was only 10.42%. The results of indica and japonica classification by ILP molecular markers and Cheng＇s index were relatively consistent. The correlation coefficient between the japonica proportion index and morphology index was 0.794＊＊, while that between the indica proportion index and morphology index was -0.7662＊＊. ILP markers could be used to accurately detect the proportion of indica/japonica content in the genome of a rice variety. The results of indica-japonica differentiation analysis could make reasonable explanation for that the hybrids obtained from indica-japonica type restorer lines had obvious heterosis. This conclusion would provide important guidance in efficient use of beneficial genes of inter-subspecific hybrid rice.

Subspecific Characteristics and Classification of Rice Varieties Developed Through Indica and Japonica Crossing

Six characteristics, i.e., hull color, chaff and leaf pubescences, length of 1st and 2nd rachis, grain length/width ratio andphenol reaction, of rice progenies from indica and japonica crossing were studied using the Chengs index classificationmethod. The results indicated that F1 generations performed more like indica, while F2 generations were approximately ina normal distribution. Both of the rice progenies were more affected by indica and female parents than by japonica andmale parents. Among the six Chengs index traits of the parents and F1 generations, and between the traits and Chengsindexes, significant correlations (both at a=0.05 and a=0.01) were found in most cases. No significant correlations werefound among the 6 Chengs index traits of F2 generations in most cases, but significant correlations (a=0.01) existedbetween these traits and Chengs indexes. The six Chengs index traits of F2 ranged successively, and many individualsshowed over-parent genetics, with the same trends in both direct cross and reciprocal cross. Among the 6 index traits,chaff and leaf pubescences almost presented in a two-peak value, while the others in a mono-peak value. The hull color,phenol reaction and length of 1st and 2nd rachis were distributed in deviation, with the first two traits presented more injaponica individuals and the last trait more in indica. The grain length/width ratios were nearly in a normal distribution.

Genetic analysis of morphological index and its related taxonomic traits for classification of indica/japonica rice

A doubled haploid population derived from anther culture of ZYQ8/JX17 F1, a typical indica and japonica hybrid, was used in this study. Morphological index and its related taxonomic traits were investigated in 121 DH lines. The quantitative trait loci (QTLs) for morphological index and its related taxonomic traits were analyzed. Two major QTLs for leaf hairiness, three QTLs for length/width of grain, one QTL for color of hull when heading, one QTL for hairiness of hull, two QTLs for length of the first and second panicle internode, and one major QTL and two QTLs for phenol reaction were detected. Four QTLs for morphological index were also identified on chromosomes 1, 3, 4 and 6, respectively, three of which on chromosomes 1, 3 and 6, respectively, were found to be located in the same chromosome regions where some QTLs for the related taxonomic traits were located.

The Relation between Genetic Difference for Parents of Hybrid Rice and Heterosis

Exploring the indica-japonica differentiation in parents of hybridization can provide theoretical bases for utilizing inter-subspecific heterosis. In this study, 5 sterile lines and 18 self-bred restorer lines were used as female parents and male parents respectively. Then 90 combinations were constructed by incomplete diallel cross followed by relationship analysis between parental Cheng’s index difference value and Euclidean distance and heterosis. The results showed a significant correlation between several phenotype values, super male parent heterosis and control heterosis and Euclidean distance or Cheng’s index difference value. However, it was no significant correlation for yield. Further analysis found a common interval, 3.41 - 3.46 for Euclidean distance and 3 - 4 for cheng’s index difference value of parents, which was significant or high significant positive correlated with phenotype value, super male parent and control heterosis of main yield traits. This illustrates that the larger the genetic difference of parents was, the stronger the heterosis combinations were, when the genetic differences of parents were in an appropriate range.

利用ILP标记分析水稻籼粳杂交亲本和衍生系的籼粳分化

【目的】揭示水稻籼粳杂交亲本和衍生系的籼粳分化度,为培育实用型籼粳亚种间杂交稻提供理论和实践依据。【方法】以通过不断聚合和累加不同广亲和基因与恢复基因的方法,历时21年,4个育种阶段,涉及18个籼粳杂交亲本和39个衍生系为研究材料,采用籼粳特异ILP分子标记(水稻内含子长度多态性分子标记)和程氏形态指数法进行籼粳分化度检测。【结果】57个供试材料基因组DNA在所检测位点上均存在籼粳分化。18个亲本共检测出4个粳稻、5个偏粳、8个偏籼和1个籼稻类型。在18个亲本中,明恢63和9308的粳稻成分分别为12.50%和33.33%;粳型恢复系C418的粳稻成分仅有31.25%。39个籼粳杂交衍生系共检测出1个粳稻、11个偏粳、20个偏籼和7个籼稻类型。其中,粳型衍生系明恢502的粳稻成分仅占10.42%。ILP标记法与形态指数法判定籼粳分类结果的吻合度较好,粳稻成分指数、籼稻成分指数与程氏指数综合值的相关系数分别为r=0.794**和r=-0.7662**。【结论】ILP标记具有准确检测籼(粳)成分比例的功能;研究籼粳分化可以合理解释籼粳型恢复系配组的杂交稻表现明显杂种优势的原因,对有效利用籼粳亚种间优良基因具有重要作用。

甬优系列杂交稻组合开花期耐冷性评价

以籼粳杂交稻甬优系列及杂交籼稻钱优2号和常规粳稻浙粳88为材料,于主茎见穗开花日起,用人工气候箱低温(17℃)和适温(25℃)分别处理4d和7d,以室外自然温度为对照,研究不同籼粳成分水稻低温胁迫下籽粒的结实特性。结果表明,低温处理显著降低甬优系列的籽粒结实率和穗重,低温胁迫效应以处理7d较大。按照耐冷性指数来划分,甬优538、浙粳88、甬优10号、甬优6号和甬优15号为耐冷型,甬优8号、甬优12号、甬优9号和甬优17号为冷敏感型,其余为中间型。此外,甬优系列耐冷型与冷敏感型籼粳成分并无明显的差异。进一步分析表明,低温处理7d,相对冷敏指数与水稻结实率和空粒率极显著相关(r=-0.9552,0.9602)。

籼粳稻杂交分类性状遗传研究初报

应用程氏指数法研究了不同类型杂交组合。结果表明：粳×籼Ｆ１为偏籼型，Ｆ２呈正态分布，大部分为籼粳中间型。粳×爪Ｆ１为偏粳型， Ｆ２为偏粳型和粳型。粳×粳Ｆ１与Ｆ２均为粳型。程氏指数法叶毛、稃毛、 穗壳色、ｉ～２穗节长、籽粒长宽比、酚反应６个分类性状间相关密切，对总分均有较大贡献，适于分析籼粳交Ｆ２以后各世代。粳×籼Ｆ２代各性状的分离除酚反应为双峰曲线外，其它５个性状均呈单峰曲线分布；除穗节长性状具有超亲现象外，其它５个性状均介于双亲之间，为部分显性。抽穗期与亲本及Ｆ１程氏指数呈极显著的负相关，结实率与Ｆ２程氏指数呈极显著的负相关。

“Lemont/特青”重组自交系的六性状籼粳分类研究

研究了287个“Lemont／特青”重组自交系的六个籼粳分类性状（程氏指数法）和154个RFI．P位点的遗传组成。群体的六性状总分呈连续分布，略偏向粳型，该方法将把大部分株系分入籼粳中间类型。遗传组成的分布略偏向特青并有更多的极端株系，六性状总分和分子标记的相关不明显。还就单个性状的分布和性状间重组情况，以及不同性状间及其与总分间的相关关系进行了分析。

江苏省杂草稻的传播与籼粳分化研究

21世纪初,杂草稻仅在江苏省局部区域发生,目前已扩大到全省,并对粳稻的高产和稳产造成严重威胁。为了掌握其快速发生机制,便于杂草稻的防除工作,需要进一步明确江苏省13市杂草稻是独立发生还是相互传播,以及江苏省杂草稻籼粳地理分布。采集了江苏省13个市58个样地的58个种群,总计205份的杂草稻样品。所有样品在南京农业大学江浦农场田间种植,并测量了38个形态学性状和6个程氏指数鉴别性状。欧氏距离聚类分析,表明江苏省13个市的杂草稻是相互混杂的。籼粳地理分布表明,江苏省杂草稻主要以籼型和偏籼型为主,籼型和偏籼型杂草稻在全部58个样点中都有分布,分别占样品总量的54.15%和42.40%;偏粳型和粳型仅分布于6个样点(淮安、苏州、盐城与扬州),分别占样品总量的2.93%和0.48%。此外,对比江苏省杂草稻的籼粳地理分布与江苏省地方品种的籼粳地理分布,未显示对应关系。籼粳比例和地理分布揭示了江苏省杂草稻主要为籼型,其中极少数为粳型杂草稻,粳型杂草稻的比例与杂草稻和栽培稻之间的自然基因漂移比例相近。

水稻粳型亲籼系籼粳型属性的程氏指数鉴定

为了提高鉴定粳型亲籼系籼粳型属性的准确性 ,用程氏指数鉴定了待测粳型亲籼系及其杂交后代的籼粳型属性 .结果表明 :用程氏指数鉴定粳型亲籼系的籼粳型属性的结果准确率较高 ,且年度间和季度间的稳定性好 ;偏粳型品种与籼型或偏籼型品种杂交 ,其 F1 多为籼型和偏籼型 .用程氏指数法从 15个待测粳型亲籼系中鉴定出 1个粳型品系和 4个偏粳型品系 .另外 ,秧苗的 KCl O3抗性可作为鉴定粳型亲籼系籼粳型属性的一个指标 。

利用InDel标记量化中国栽培水稻微核心种质的籼粳成分

利用34对鉴定籼粳指数的InDel标记对184份栽培稻微核心种质的籼粳指数进行量化与评价。结果表明,微核心种质中典型籼稻、籼稻、偏籼、中间型、偏粳、粳稻和典型粳稻的比例分别为53.26%、9.24%、1.63%、1.09%、3.26%、9.78%和21.74%,偏籼粳中间型的材料较少。

水稻籼粳交衍生不育系的籼粳属性鉴定及配组F_1优势初探

通过籼粳杂交培育了3份水稻不育系,分别为野败型不育系064A、协研A和光温敏不育系300S。对这3份不育系相应的保持系的籼粳属性进行了形态指数法和分子标记法鉴定。064B、协研B和300S形态指数分别为11、9和12,属于中间偏籼类型;基于分子标记的遗传距离聚类结果表明,3份材料聚为一类,也属于中间偏籼类型。通过广泛测交,发现应用籼粳杂交,在籼稻遗传背景中掺入一定比例的粳稻"血缘",培育中间偏籼型不育系,对丰富水稻育种遗传背景,配制超级杂交稻组合具有重要意义。

籼粳交重组自交系的亚种属性与稻米品质性状的关系

2006—2007年以典型籼稻七山占和典型粳稻秋光构建的重组自交系(RILs)F8的92个株系和F9的142个株系为试材,分别以程氏指数(ChI)和籼粳特异SSR标记(Dj)为群体形态分化与遗传分化的指标,同时测定11项主要稻米品质性状,分析群体稻米品质性状类型间差异及籼粳属性与稻米品质性状的相关性。结果表明,两世代RILs群体形态分化均表现为接近正态的连续分布,籼型和粳型株系数接近,遗传分化则均表现为明显偏粳的连续分布;根据ChI将RILs群体划分为籼型和粳型,除F9粒宽外两世代品质性状类型间差异均未达到显著水平;根据Dj将RILs群体划分为偏粳型和粳型,两世代粳型糙米率、整精米率、粒宽显著或极显著高于偏粳型,长宽比极显著低于偏粳型;两世代RILs群体ChI与所有品质性状的相关性均未达到显著水平;Dj与糙米率、整精米率和粒宽呈显著或极显著正相关,而与长宽比呈显著或极显著负相关。形态分化与北方粳稻品质性状没有直接关系,而遗传分化中粳稻血缘比例增加可能通过粒形间接改善碾磨品质。

云南稻籼粳亚种间功能性成分含量差异

对111份云南改良稻种和77份元阳地方稻种采用程氏指数法进行籼粳分类,比色法测定抗性淀粉、γ-氨基丁酸和总黄酮含量,并用SPSS软件对数据进行统计分析,结果表明:(1)总体抗性淀粉含量籼型>偏籼>偏粳>粳型,γ-氨基丁酸含量则相反,黄酮含量与籼粳分化的关系不明显;(2)抗性淀粉、总黄酮含量有色米>无色米,γ-氨基丁酸含量无色米>有色米。总体功能性成分含量有色米>无色米,籼稻>粳稻,糙米>精米,地方种>改良种,有色、籼型糙米功能性成分最高,揭示了籼粳分化和米色与抗性淀粉、γ-氨基丁酸与总黄酮含量的关系。

籼粳稻杂交后代蒸煮食味品质与亚种分化的关系

以2个典型籼粳稻杂交重组自交系F8群体(中优早8号×丰锦,计158株系;七山占×秋光,计142株系)为试材,利用程氏指数法鉴别其籼粳属性,同时测定稻米食味品质及淀粉RVA特征值,分析籼粳杂交后代稻米蒸煮食味品质与籼粳亚种性状特征的关系。结果表明:1)2个群体程氏指数、口感、综合评分及RVA谱特征值均呈连续分布,大部分株系介于双亲值之间;2)程氏指数与口感、综合评分及各RVA谱特征值的相关不显著或相关系数较小,依据程氏指数划分的类型间口感、综合评分及RVA谱特征值无明显差异,说明籼粳分化对稻米食味品质无直接影响;3)随着口感改善和综合评分的提高,热浆黏度、冷胶黏度、消减值降低、回复值升高,其他RVA谱特征值变化规律性不明显。

籼粳交后代中的穗型指数与亚种特性及产量性状的关系

以两个典型的籼粳交重组自交系F6群体(RILSA:中优早8号/丰锦;RILSB:七山占/秋光)为试材,分别在四川和辽宁种植,研究穗型指数(PTI)与亚种特性及产量性状的关系。结果表明,PTI在籼粳交后代中表现连续变异,籼粳交可以创造大量具不同PTI的株系,可以作为理想穗型选育的来源。生态环境对PTI有显著影响,从辽宁到四川,PTI显著变小。PTI与大多数亚种特征性状呈显著负相关。PTI在不同亚种类型间有明显差异,总体上有籼(H)>偏籼(H′)>偏粳(K′)>粳(K)的趋势,但PTI不可以作为判别亚种类型的依据,因为籼粳交后代中的PTI在不同亚种类型间交错重叠。PTI与穗部性状和产量性状大多呈负相关,两群体中绝大多数株系的PTI为中下部优势型,在产量上具有明显优势。

程式指数法和InDel分子指数法对云南元江稻属资源籼粳分化的比较研究

【目的】研究云南元江普通野生稻及其后代的籼粳属性及籼粳分化程度,为探索普通野生稻的起源演化、遗传分化及育种利用等提供理论依据。【方法】利用程式指数法和InDel分子指数法从表型到分子水平对云南元江普通野生稻(Oryza rufipogon)、栽培稻合系35号及354份渗入系后代进行粳籼属性分析。【结果】程式指数法分析结果表明:普通野生稻总分11分,为偏籼型;合系35号总分24分,为粳型;354份渗入系中有籼型材料179份、偏籼型76份、粳型25份和偏粳型74份;经InDel分子指数法鉴定发现:普通野生稻和合系35号的籼型基因频率分别为0.32和0.04,分别属于偏粳型和典型粳稻;在354份渗入系中有典型籼稻113份、籼稻84份、偏籼36份、中间类型29份、偏粳21份、粳稻24份和典型粳稻47份。综合程式指数法和InDel分子指数法分析结果表明:2种方法的拟合度高达92.42%,仅普通野生稻及26份渗入系的籼粳类型划分结果存在偏差。【结论】程式指数法和InDel分子指数法鉴定稻属资源籼粳属性的结果基本一致,2种方法结合应用可有效分析普通野生稻及其渗入系后代的籼粳属性;普通野生稻籼粳属性在表型和分子水平上存在一定差异,可能与普通野生稻籼粳分化不彻底有关。云南元江普通野生稻渗入系后代的籼粳类型丰富、分化明显,是重要的育种材料,也是研究普通野生稻起源、进化及分类的宝贵资源。

9份水稻籼粳交衍生株系属性鉴定及其遗传效应分析

通过形态指数法和分子标记法对9个籼粳交衍生系进行籼粳属性鉴定,结果表明:获得了2个偏籼类型材料。采用等位基因的加性-显性遗传模型分析偏籼型水稻的产量相关性状的遗传效应,结果表明,每穗总粒数和每穗实粒数主要受到基因加性效应的影响;播始历期、主穗长、单株有效穗数和结实率主要受到基因显性效应的影响。