水稻与高梁属间远缘杂交花粉管行为观察

水稻和高粱是禾本科的两个异属作物,因其遗传距离较远,杂交表现不亲和,结实率极低,难以获得种子.为初步了解水稻与高粱属间远缘杂交花粉管行为,探索该远缘杂交的发生过程,本实验以籼稻珍汕97A×珍汕97B和Ⅱ-32A×Ⅱ-32B两个组合为对照,对珍汕97A×晋江多枝高粱和Ⅱ-32A×晋江多枝高粱两个属间远缘杂交组合的花粉管行为作初步的观察与研究,结果表明晋江多枝高粱花粉粒能象水稻花粉粒一样在水稻柱头上正常萌发,花粉管在花柱及子房中生长与伸长,有些能最终到达子房的基部;同时高梁花粉管生长也出现诸如不能进入花柱、胼胝质不规则堆积、花粉管末端钝化等一系列的异常表现,致使不少花粉管停滞生长.     

不同生态环境下陆地棉转基因抗虫杂交棉遗传效应及杂种优势分析

 【目的】探讨不同生态环境下陆地棉转基因抗虫杂交棉遗传效应及杂种优势，为抗虫杂交棉选育和应用提供指导。【方法】采用MINQUE统计方法、ADE遗传模型对10陆地棉亲本材料及其24个F1转基因抗虫棉杂交组合（6×4）的产量和品质性状的3个生态区试验资料进行分析。【结果】单铃重、衣分、皮棉产量和伸长率、2.5%跨长、比强度、麦克隆值主要受遗传主效因控制,子棉产量、亩铃数和整齐度受环境效应影响非常明显；在遗传主效应中，除铃重外，其余4个产量性状中显性效应值大于加性效应值,5个品质性状加性效应值均大于显性效应值；通过群体平均优势（Hpm）和群体超亲优势（Hpb）与环境互作效应分析，皮棉产量、衣分稳定性较好，子棉产量和铃数稳定性较差；产量性状与环境互作效应值较大，而品质性状与环境互作效应值较小。【结论】产量性状表现出一定的杂种优势，而品质性状的杂种优势表现不明显；棉花品质性状在一个环境可选育，而产量性状必需结合生态环境选育,才能达到育种目标。     

小麦主要性状的遗传模型分析

选用８个小麦品种采用双列杂交方法组配了２８个杂交组合,对其主要性状进行了遗传研究,结果表明：单株粒重和穗数符合加快模型;千粒重,穗粒数,结实小穗数,穗长符合加性－显性模型,株高,颈长符合加性－显性－上位性模型。     

玉米杂交当代子粒灌浆特性的研究

对粒重不同的２个纯合稳定普通玉米自交系和２个爆裂玉米自交系及各自间正,反交４个杂交组合杂交当代的子粒灌浆特性研究结果表明：（１）各组合杂交当代的百粒重均高于母本自交系,超母本优势均为正值,平均及超父本优势依父,母本粒重的相对大小不同而异;（２）不同部位子粒百粒重均表现下部．〉中部〉上部,且授粉后２０ｄ差异较小,之后差异较大;（３）灌浆速率的高低和有效灌浆期 的长短时导致不同材料及不同部位子粒百粒重     

Wide hybridization and introgression breeding in safflower: Effectiveness of different selection methods

Possibility of using interspecific hybridization to increase genetic diversity of drought tolerance in safflower (Carthamus tinctorius L.) and effectiveness of different selection methods is poorly understood. The main objectives of this study were to evaluate the effectiveness of (a) interspecific hybridization to expand genetic diversity in safflower for agronomic traits and drought tolerance in advance generations and (b) different selection methods (direct vs. indirect) for improving seed yield. Interspecific hybridizations were performed between species of C. tinctorius × C. palaestinus (TP), C. palaestinus × C. oxyacantha (PO) and C. tinctorius × C. oxyacantha (TO). Based on the field screening of genotypes in F3 generation, four groups of selected genotypes (derived from combination of direct and indirect selection under both drought and normal environments along with selection based on drought tolerance index (STI)) were evaluated in F4 and F5 generations. Indirect selection for seed yield was significantly more efficient than direct selection. Selection in stress environment resulted to more efficiency than selection in normal environment. No significant difference was observed between direct selection and selection based on STI. The result showed that TP was the best population to combine high seed yield and drought tolerance in safflower.     

斑茅F1杂交可育亲本选择及其回交后代鉴定和主要经济性状

选用8个Badila(甘蔗热带种)与斑茅属间杂交F1品系与9个甘蔗栽培品种配制了24个回交组合，其中6个F1品系的13个组合杂交可育，共获346株BC1实生苗．经同工酶分析，其中320个株系具有斑茅的特征酶带，为斑茅的真实后代。在杂交可育性和BC1后代主要经济性状方面，斑茅F1品系间和杂交组合问均存在显著差异。斑茅BC1后代的产量性状和糖分仍与甘蔗栽培品种有较大差距，但各性状的最大值已与栽培品种的相当。初步研究结果表明，YC96—40和YC95—41是较好的斑茅F1亲本材料。     

大豆不同亲本正反交后代开花期叶片叶绿素含量遗传研究

2002年,对大豆不同亲本正、反交F3、BC1F2开花期叶片叶绿素含量遗传进行了初步比较研究,结果表明,各组合F3开花期叶片叶绿素含量平均值偏向于母本,广义遗传力的大小与母本值关系密切,母本值高的组合F3广义遗传力明显高于母本值低的组合,各组合正、反交F3开花期叶片叶绿素含量的变异度与母本值也相关,母本值高的组合F3变异度大于母本值低的组合;BC1F2开花期叶片叶绿素含量的遗传表现与组合的父母本和回交亲本的开花期叶片叶绿素含量直接相关.     

Crosses Involving W. Rimpau's Triticale

One hundred years after the creation of the first true triticale crosses of Rimpau , several recent cultivars of triticale and rye have been crossed with two of them. Recombinants of the awned type of Rimpau 's triticale (10) with ‘Grado’, ‘Lasko’ and ‘Otello’ exhibited a prolonged vegetative period, a shorter straw, an improved lodging resistance, good yielding capacity and higher disease resistance as compared to ‘Lasko’.     

Possibility of genetic improvement of pigeonpea (Cajanus cajan (L.)Millsp.) utilizing wild gene sources

Summary Various wild relatives of pigeonpea,Cajanus cajan, namely some species ofAtylosia andRhynchosia, possess desirable characteristics that could be utilized for effecting genetic improvement of this crop. In total 73 cross combinations among two cultivars ofC. cajan and one accession each of eightAtylosia species and one ofRhynchosia were attempted. Twelve hybrids were obtained. Seven of these were analysed for F₁ fertility and their utility for agronomic improvement of theC. cajan. Fertility behaviour of the different F₁ hybrids varied and indicated that potential of gene transfer between the two genera,Atylosia andCajanus, was as good as within the genusAtylosia. From F₂ and F₃ families ofC. cajan × A. scarabaeoides andC. cajan × A. albicans, plants were selected with greater physiological efficiency and agronomic superiority. The prospects of transferring pod borer resistance and higher seed protein content from someAtylosia species to pigeonpea are discussed.     

Crossability relationships among wild potato species with different ploidies and Endosperm Balance Numbers (EBN)

Three wild potato species with different ploidies and Endosperm Balance Numbers (EBN) were crossed in a complete diallel design and the development of the embryo and endosperm as well as the type of seeds produced were analyzed. The compatible crosses – intraspecific intra-EBN and interspecific intra-EBN – produced more than 89% plump seeds, whereas in the incompatible crosses – intraspecific inter-EBN and interspecific inter-EBN – more than 85% of the seeds were not as well developed or were shrunken. The histological analysis revealed that inviable seeds had less developed or collapsed endosperms and thicker endotheliums than viable ones. A gradation of crossabilities was observed among species. The self-compatible species Solanum acaule had good performance as a female but not as a male parent. Among the self-incompatible species, Solanum gourlayi was the best male parent but had a poor performance as a female, whereas Solanum commersonii had an intermediate behavior. Differences in crossabilities among genotypes within species were also observed. These results can not be solely explained by the EBN hypothesis. It is, therefore, suggested that the EBN may be part of a more complex system of interspecific barriers acting at the pre- and post-zygotic levels. This revised version was published online in July 2006 with corrections to the Cover Date.