不同组合杂种小麦旗叶光合优势特点的研究

为揭示不同亲本组合的化杀型杂种小麦旗叶光合优势形成的生理基础，对杂种小麦1F1和2F1进行了研究，结果表明：1F1和2F1旗叶光合速率在旗叶衰老后期都高于亲本和对照，在全展初期则优势不显著或不具优势；1F1和2F1旗叶的叶源量均高于亲本和对照，但优势来源不同，1F1的优势起因于其叶片光合功能期(叶绿素含量缓降期和光合速率高值持续期)的延长，2F1的优势则由叶片光合功能期延长和光合速率提高共同作用所致。     

杂种小麦及其亲本光合碳同化特性的研究

供试化杀型(CHA), T型三系杂种小麦及各自亲本在旗叶一生中的净光合速率(PO、叶绿素含量(Ch1)和可溶蛋白含量(Sp)均在全展时达到最大值,以后逐渐下降。在春季生育期中群体光合速率(CAP)的变化趋势呈单峰曲线,于开花期达到最大值。与亲本和对照相比,杂种小麦在生育期间于上述性状上多表现正向优势,且优势随生育进程不断增     

多环境下陆地棉染色体片段代换系及F_1皮棉产量与纤维品质的表型分析

以1套陆地棉染色体片段代换系为亲本材料,采用株系间随机成对杂交组配F1,在5个环境下鉴定片段代换系亲本及F1的皮棉产量与纤维品质性状表现。结果表明,与轮回亲本(中棉所36)相比,F1在铃重与皮棉产量性状上具有一定的对照优势,亲本与F1的纤维长度与比强度均表现出明显的对照优势,且环境间表现一致。F1铃重、衣分与皮棉产量在各个环境下的中亲优势均值全部为正,且相对较大。除个别环境外,纤维长度、马克隆值与比强度的中亲优势均值也全部为正,但数值相对较小。片段代换系及F1的遗传变异丰富,部分亲本与F1在多个环境下的综合表现优异,其皮棉产量与纤维品质得到同步提高,群体材料的遗传改良与杂种优势利用具有广阔前景。     

2个小麦种质材料育种相关性状的初步分析

对引自德国的品种‘16亲10188’、大穗抗病种质‘YB’等2个小麦种质的育种特性进行初步鉴定。利用西南麦区主栽品种和地方品种分别与其杂交组配，并对其F1代及其亲本进行产量、抗病相关性状的调查。‘16亲10188’具有矮秆、多粒、抗条锈病、抗白粉病的特性，在F1组合中，其矮秆表现为部分显性，高穗粒数表现为隐形或部分显性，条锈病抗性表现为显性，白粉病抗性表现为隐性；‘YB’为大穗、寡分蘖、抗条锈病、抗白粉病材料，其长穗表现为部分显性，寡分蘖表现为隐性，穗粒数、粒重性状在F1中表现为杂种优势，抗白粉病表现为隐性。‘16亲10188’的降秆、条锈病抗性在育种中可以进行早代选择，高穗粒数、抗白粉病性状可以在高代系群体中进行选择；‘YB’的F1组合在产量上表现出显著的杂种优势，可作为杂交小麦育种的优良亲本。     

杂种小麦花后干物质积累转运动态和分配

选用两个杂种及其亲本和对照7个材料, 进行了开花后干物质积累转运和分配规律的研究。 结果表明： 杂种小麦叶面积大, 生物量高, 灌浆强度大, 每日千粒重达1677～1812 mg, 超双亲平均值(MP)和对照(CK)8.6%～26.1%, 灌浆持续时间长1.4～3.1d, 是形成粒重优势的关键所在。 与亲本相比, 化杀杂种CH-1的干物质转运率(TR)     

杂种小麦光合特性的初步研究

对化杀型杂种小麦与普通小麦叶光合特性的比较研究表明，供试杂种小麦上部叶片倒３叶、旗叶一生中比普通小麦对照品种具有较高的叶绿素含量、净光合速率。ＲｕＢＰｃａｓｅ活性和ＲｕＢＰｏａｓｅ活性。杂种小麦叶片与对照相比在叶绿素含量缓解（ＲＳＰ）上优势较小，光合速率高值持续期（ＰＡＤ）和ＲｕＢＰｃａｓｅ含量则不具有优势。这表明，杂种小麦上部叶一生中光合速率的提高受到ＲｕＢＰｃａｓｅ含量的影响较小，而在很大程度     

甘蓝型油菜两类同核异质杂交种遗传效应的比较分析

探究甘蓝型油菜化学诱导型雄性不育(CIMS)和细胞质雄性不育(CMS)杂交种间遗传效应的差异,为利用CIMS和CMS途径进行油菜超高产育种提供依据。以3个甘蓝型油菜CMS和同核CIMS与4个恢复系按照ACII不完全双列杂交(3×4)配制2套同核异质杂交种及其亲本为试验材料,进行了连续2年的田间试验,将29个性状指标划分为农艺、产量、品质3类性状,利用QGA Station Microsoft分析软件中的加-显性(AD)模型进行了统计分析,结果表明:与同核CIMS杂种比较,CMS杂种农艺、产量和品质性状的加性方差分别高21.85%,72.11%,13.48%,显性方差分别高3.58%,94.44%,56.90%,加性方差比率分别高39.29%,8.94%,-7.05%;显性方差比率分别高15.83%,4.30%,89.97%。CIMS杂种与同核CMS杂种间在F1的差异大小为农艺性状产量性状品质性状,在F2为产量性状农艺性状品质性状;在F1、F2,与同核CIMS杂种比较,CMS杂种的群体平均优势农艺性状分别低31.61%,32.74%,产量性状高72.82%,76.95%,品质性状指标则低58.81%,22.63%;在F1、F2,CMS杂种的群体超亲优势为农艺性状分别低75.35%,76.33%,产量性状低47.53%,32.90%,品质性状高14.09%,20.53%。CMS杂种的农艺性状、产量性状的狭义遗传率则分别比CIMS杂种高47.77%,54.31%。CMS不育细胞质对油菜杂种的性状产生了影响,且不同性状受到的影响程度不同;即CMS杂种的性状受亲本基因型的控制程度高于CIMS杂种;对CMS杂种的亲本应在早期世代加强选择,主要利用亲本的一般配合力(加性效应)进行选择,而CIMS杂种的亲本则应在高世代加强选择;亲本的性状和亲本的特殊配合力(显性效应)对2类杂交种的表现都有较大影响,因而亲本的选配对杂种的表现有很大的决定性。     

化杀杂种小麦灌浆规律及粒重优势

对化杀杂种小麦灌浆特性及播期、密度、灌水效应的研究表明，其灌浆规律与常规（亲本）品种相同，籽粒增重遵循慢—快—慢的节律变化，同时具有自己的特性。杂种的快速增重期较对照早１～３天，灌浆速度峰值超对照优势达２４．７１％～４６．３４％，且持续时间长，灌浆速度的峰面宽，因而单粒重比对照高６～１１ｍｇ，但不同部位小穗间的粒重差异依然存在，且较对照大。杂种的灌浆特性与亲本有关，但仍表现出明显的超亲优势。播期、密度、灌水等影响灌浆进程，因而可通过亲本选配、强优势组合筛选及农艺措施调节进一步发挥杂种的粒重优势     

预测粳型水稻F1杂种优势的关键DNA标记

预测杂种表现一直都是杂交育种计划的主要目标之一。本试验旨在评价粳型水稻亲本遗传相似性与F1籽粒产量杂种优势间的关系，建立基于标记预测杂种优势的策略。本试验采用不完全双列杂交设计，应用10个粳型水稻品种得到了45个F1杂种。将亲本和杂种种植在施中等氮肥和不施氮肥条件下，对其籽粒产量进行评价。采用188个SSR标记和／或者129个RAPD引物对亲本品种进行基因型分类。基于全部标记的遗传相似性估计值与杂种优势间没有显著相关。     

旱地杂种小麦优势测定及亲本组配模式研究

在旱作条件下,选用水旱两种生态型的小麦品种各4个,组成4×4不完全双列杂交,分折了8个主要农艺性状的超标优势和杂种优势,并对其遗传机制进行研究.结果表明水旱品种间杂交,其F1杂交优势普遍存在.F1杂种生态型是以千粒重为主,兼顾穗粒数,表现为重穗型.杂种F1产量性状变异受水地亲本影响大,旱地亲本对株高、穗下节长,单株穗数等与抗旱性密切的性状影响明显.水旱两种生态型品种杂交,易于实现抗旱与丰产的有机结合,是一种值得重视的抗旱育种杂交模式.     

Heterosis for yield and related characters in pea

Summary To determine the levels of heterosis in F1 hybrids, four current pea (Pisum sativum L.) cultivars from southern Australia were used as female parents and crossed with 18 introduced genotypes. The 22 parents, 72 F1 hybrids and, depending on the environment, either 54 or all 72 F2 families were grown in replicated plots in four environments. Grain yield, total dry matter, harvest index, branches per plant, pods per plant, seeds per pod, hundred seed weight, plant height, onset of flowering and flowering periods were evaluated. For both the F1 and F2 generation, heterosis was determined as the superiority over the mid-parent and also over the better parent. In addition, the superiority over the best commercial cultivar was calculated. Most hybrids were higher yielding than their mid-parent but were less stable in yield across environments. Four F1 hybrids were significantly higher yielding than the best parent, by up to 26%. There were significant correlations between F1 hybrid and mid-parent value for plant height, pods per plant and hundred seed weight but not for yield. Overall, grain yield heterosis was mainly due to more pods per plant in the hybrids. The level of heterosis for yield in a poor yielding environment was higher than that in a high yielding one. Both additive and non-additive gene effects were important in the expression of all studied traits. The average level of heterosis for grain yield and total dry matter in the F2 population was half of that in F1 hybrids. The low level of inbreeding depression from the F1 to the F2 generation suggested that epistatic gene action also contributed to the expression of grain yield. Some F2 populations maintained the high yield levels of the corresponding F1 hybrids.     

K,V型杂种小麦优势的研究

利用５（Ａ）×２（Ｒ）两组亲本杂交的１０个杂种及其相应的亲本材料，探讨高产条件下Ｋ、Ｖ型小麦的杂种优势。结果表明：单株产量有很强的杂种优势，７个组合超双亲平均值为７．１１％～２５．１％，其中３个为１５．７％～２５．１％，４个组合超标优势２．４％～１８．１％。Ｋ、Ｖ型杂种优势的主要表现是千粒重的增高，其次是穗粒数，有３个组合超双亲平均值。单株穗数的减少对杂种产量有影响，选择多穗亲本，对提高杂种的穗数有效     

CHA杂种小麦灌浆优势规律研究

以4个CHA杂种及其亲本和CK为材料, 采用数学模型分析、 相关分析、 通 径分析等方法, 研究了CHA杂种灌浆优势及其动态规律和与气象因子的关系, 结果表明 , (1) 4个CHA 杂种籽粒干物质积累动态过程均存在杂种优势, 最终干物质积累均存在 超亲优势, 最终干物质超亲优势形成过程有灌浆全期形成、 灌浆中后期形成和灌浆后期     

A comparison of cytoplasmic and chemically-induced male sterility systems for hybrid seed production in wheat (Triticum aestivum L.)

A comparison of two male sterility systems was carried out in wheat for hybrid seed production and hybrid performance. Seventeen hybrid combinations based on Triticum timopheevi cytoplasm were compared with their genetically equivalent CHA-facilitated combinations. The same set of restorer lines was used as parents in CMS- and CHA-based hybrids to maintain genetic equivalence. In the first experiment aimed at study of female line behavior and crossed seed production, the CHA treated lines showed significantly shorter heights whereas CMS lines were similar to the control. The two systems were equally effective in sterilizing rate. The outcrossing percentage of the CMS lines was almost twice that of the CHA treated lines. Thousand-grain weight of the crossed seeds on CMS lines was greater than on the CHA treated lines and control. On average, the germination percentage of seeds on CMS lines was double that of the CHA treated lines and the percentage of effective outcrossed seeds in CMS lines was 3 times more than that from CHA treated lines. The second experiment was conducted to examine the yield performance of the hybrids derived from the two systems of male sterility. A total of 40 entries including 20 hybrids and 20 parents were evaluated in the experiment. The mean grain yield of the CMS-based hybrids was greater than that of the CHA-based hybrids,the B and R lines. All the CMS-based hybrids showed significantly higher grain yields than their better parents whereas all the CHA-based hybrids, except two,showed no significant yield increases over their better parents. Possible reasons for differences in CMS- and CHA-based hybrid performance are discussed. This revised version was published online in July 2006 with corrections to the Cover Date.     

Hybrid performance for yield and yield components in cardamom (<Emphasis Type="Italic">Elettaria cardamom</Emphasis> Maton)

Cardamom is an important high value spice crop. Hybrid breeding is discussed for some time, but there is no information for cardamom. Eight genetically diverse cardamom lines were crossed in a diallel to evaluate the performance of hybrids and determine heterosis over mid-parent, better-parent and standard control for yield and yield components. The study was undertaken for a period of 3 years from 1988 to 2001 (Experiment I). Hybrids generally showed good overall performance for most of the characteristics compared with parents. Ten of the 56 hybrids significantly out-yielded the standard control (RR 1). Substantial mid-parent (MPH), better-parent (BPH) and standard (SH) heterosis were observed for the majority of the characteristics studied. Further evaluation of selected hybrids for yield and disease resistance during 2002–2007 (Experiment II) led to the identification of two cross combinations (CCS 1 × NKE 19 and RR 1 × NKE 12) with high yield and mosaic resistance. The study revealed that cardamom hybrids with high yield potential, desirable quality characteristics and mosaic resistance can be developed from appropriate parents through heterosis breeding. This is the first report of heterosis in cardamom for yield and yield contributing characteristics.     

Hybrid performance and heterosis in spring bread wheat, and their relations to SSR-based genetic distances and coefficients of parentage

Development of hybrids is considered to be a promising avenue to enhance the yield potential of crops. We investigated (i) the amount of heterosis observed in hybrid progeny, (ii) relative importance of general (GCA) versus specific (SCA) combining ability, and (iii) the relationship between heterosis and genetic distance measures in four agronomic traits of spring bread wheat. Eight male and 14 female lines, as well as 112 hybrids produced in a factorial design were grown in replicated trials at two environments in Mexico. Principal coordinate analysis based on Rogers' distance (RD) estimates calculated from 113 SSRs revealed three different groups of parents. Mid-parent heterosis (MPH) for grain yield averaged 0.02 t ha⁻¹ (0.5%) and varied from −15.33% to 14.13%. MPH and hybrid performance (F1P) were higher for intra-group hybrids than for inter-group hybrids, with low values observed in inter-group crosses involving two non-adapted Chinese parents. Combined analyses of variance revealed significant differences among parents and among hybrids. Estimates of GCA variances were more important than SCA variances for all traits. Tight correlations of GCA with line per se performance, and mid-parent value with F1P were observed for all traits. In contrast, correlations of MPH with RD and coefficient of parentage were not significant. It was concluded that the level of heterosis in spring wheat was too low to warrant a commercial exploitation in hybrids. SSRs proved to be a powerful tool for the identification of divergent groups in advanced wheat breeding materials.     

陆地棉F_2纤维品质性状杂种优势的遗传分析

本研究根据加性─显性与环境互作的遗传模型，分析了陆地棉１０个杂交亲本和２０个Ｆ１五个纤维品质性状的两年试验资料，估算各项遗传方差分量和成对性状间各项遗传效应的相关，预测了不同年份Ｆ２杂种优势的遗传表现。各纤维品质性状主要受加性效应的影响。其中纤维长度、纤维强度和麦克隆值３个性状还受到基因型×环境互作效应的影响。基因型×环境互作效应对纤维整齐度和纤维伸长率两个性状影响均不显著。遗传相关分析表明，杂交后代皮棉产量与纤维长度、纤维整齐度、纤维伸长率和纤维细度间可进行同步改良，皮棉产量与纤维强度同步改良较为困难。杂种早代皮棉产量高的组合其纤维强度也较好。Ｆ２纤维品质性状杂种优势的均值一般较小。此外还分析了组合纤维长度、纤维强度和麦克隆值杂种优势在不同环境中的表现。     

棉花杂种优势与几种生理生化指标的相关性

对８个陆地棉杂种及其亲本的四种生理生化指标进行了测定，并研究了这些指标与杂种产量优势的相关性，结果表明：幼芽匀浆互补法对Ｆ１皮棉超亲优势、中亲优势的预测相符率分别为８７．５％和７５．０％；杂种萌动种子ＡＴＰ含量普遍高于双亲平均值。超亲优势、中亲优势与杂种ＡＴＰ含量及双亲ＡＴＰ含量的平均值均呈正相关，且中亲优势与杂种ＡＴＰ含量相关显著（ｒ＝０．７１８８，Ｐ〈０．０５）；杂种产量优势与盛蕾期、盛花期的     

Genetic analysis of rapeseed self-incompatibility lines reveals significant heterosis of different patterns for yield and oil content traits

Self‐incompatibility is one of the most effective approaches to utilizing heterosis in oilseed rape around the world. To evaluate the heterosis of double low self‐incompatibility, the possibility of combining seed yield and oil content, and the genetic effects of parents on their hybrid progenies, a 2‐year field trial using a 3 × 22 NC II mating design was conducted during the 1999‐2001 growing seasons in Wuhan, China. Significant differences in seed yield per plant and seed oil content were observed among the F1 hybrids and between F1 progenies and their parents. However, the heterosis for seed yield per plant was much greater than that for seed oil content. Mid‐parent heterosis and high‐parent heterosis of seed yield per plant ranged from 5.50 to 64.11% and from –2.81 to 46.02%, while those of seed oil content ranged from –1.55 to 7.44% and –3.61 to 6.55%, respectively. Non‐additive genetic effects were a major mechanism that accounted for the yield heterosis in addition to additive effects. In contrast, seed oil content heterosis was mainly dependent on an additive genetic effect. General combining ability (GCA) determined the stability of hybrid cultivars. In hybrid breeding, parental materials might be selected by the sum of GCAs and variances of special combining abilities (SCAs) of female and male parents for traits affected by both additive and non‐additive effects, and by the sum of GCAs of two parents for traits controlled mainly by additive effects. Primary branches and their siliques were the most important yield traits.