Prediction of heterosis using QTLs for yield traits in rapeseed (Brassica napus L.)

Three double low (erucic acid and glucosinolates) self-incompatible lines and 22 varieties from different origins were selected to produce 66 hybrids according to a NC II mating design. Field experiments for identification of hybrid performance and heterosis were conducted in two successive rapeseed growing seasons in Wuhan, China. After heterosis identifications, SI-1300 and Eagle were chosen to construct an F₂ segregating population. One hundred and eighty four F_2:3 lines were planted at Wuhan and Jingmen to test yield traits. F₂ plants and the 25 parents were analyzed using simultaneously AFLP (amplified fragment length polymorphism) and SSR (simple sequence repeat) markers. A total of 270 and 718 polymorphic loci were detected in the F₂ population and among the 25 parental lines, respectively. Of the 718 polymorphic loci, 178 were significantly correlated to yield traits. With the use of one-way ANOVA, 84 common QTLs were detected for 12 traits at two trial locations. Although the genetic distances based on general/specific heterozygosities and single-locus QTLs showed significant correlations with hybrid performance and heterosis for some yield traits, the determination coefficients were low. The results suggested that neither heterozygosities nor QTLs for yield traits were suitable to predict hybrid performance and heterosis in Brassica napus.     

玉米（Zea mays L.）×大刍草（Zea diploperennis L.）远缘杂交选育玉米自交系的研究

为了丰富玉米遗传变异,从1990年起,我们进行了玉米(Zea mays L.)和多年生二倍体大刍草(Zea diploperennis L.)远缘杂交的研究。经过5年8个世代的杂交、回交和自交选择,目前已获得抗逆性、抗病虫能力较强,农艺性状优良的玉米自交系14个。在测配1000个杂交组合中,所选系表现出较高的一般配合力和特殊配合力。实践证明,这是一条导入外缘种质、拓宽玉米遗传基础,进一步提高杂交种增产潜力的途径之一。     

03-19-程旺大-密穗型水稻的研究现状及展望

水稻密穗型品种通过“扩库”使产量水平有了较大提高，其育成和推广在近20a来浙江省晚粳稻品种改良及增产中起了重要作用。分析了密穗型品种的形态学特征及其生理生态特性，从群体小气候环境、物质的生产和分配、产量结构、稻曲病的发生及稻米品质和灌浆特性等方面进行了讨论。在此基础上，对密穗型水稻的研究作了展望，认为应继续加大形态类型创新和育种基础材料的创新，开展不同类型品种源库关系的研究，以及不同类型品种品质差异及其形成机理的研究。     

Cmponent Study on Flavonoids From Leaves of Dendrocalamus Latiflorus

从麻竹（Dendrocalamus latiflorus）叶中分离得到四个黄酮类化合物。经性质和光谱（UV,IR,MS,1HNMR,13CNMR等）法鉴定其结构,分别为牡荆苷（?）,芦丁（II）,山奈酚-3-O-β-D-芸香糖苷（III）,山奈酚-3-O-β-D-葡萄糖基(1-2)-α-L-鼠李糖苷（IV）。四种化合物均为首次从该植物中得到。     

棉子品质性状的遗传研究

本研究采用6个陆地棉亲本的Griffing双列杂交设计模式Ⅱ对5个棉子品质性状进行了Hayman双列遗传模型分析.结果表明,种子蛋白质和油分百分含量、种子蛋白质和油分指数及仁指都适合“加性—显性”模型.种子蛋白质百分含量和指数以显性效应为主且表现超显性;种子油分百分含量和指数以加性效性应为主且表现部分显性;仁指加性和显性效应都较重要,接近完全显性.在所研究的亲本中,不同性状的显、隐性基因频率,正负效应基因的比例,显、隐性基因的方向及狭义遗传力等都明显不同.     

Introgression of alleles of the isozymic locus glucosephosphate isomerase-2 (GPI-2) from the CC genome of Brassica carinata to the CC genome of Brassica alboglabra and their independent segregation from seed colour

A yellowish brown‐seeded Brassica alboglabra was resynthesized from a (B. alboglabra×Brassica carinata) ×B. alboglabra cross, followed by self‐pollination. The resynthesized B. alboglabra lost the allele of the isozymic locus glucosephosphate isomerase‐2 (GPI‐2) from natural B. alboglabra, which was replaced by an allele from the corresponding genome in B. carinata. A simple Mendelian segregation of these two alleles was observed in the F₂ population of a natural × resynthesized B. alboglabra cross. Furthermore, these two alleles segregated independently from the seed colour.     

Carbon Isotope Discrimination and Productivity in Field-Grown Barley Genotypes

Five barley genotypes of different origins were used to examine the relationships between carbon isotope discrimination (Δ) and grain yield, yield components, dry aerial biomass and harvest index under rainfed and irrigated Mediterranean conditions. High positive correlations were found between Δ and grain yield and harvest index under both water conditions, suggesting that Δ may represent efficiency of dry matter partitioning to the grain. This hypothesis was also supported by the positive correlation found between Δ and thousand-grain weight when all the data were considered. The two drought-tolerant genotypes LM2887 and Tadmor presented the smallest difference between the two treatments for traits related to productivity as well as the highest Δ values. These results highlight the potential of Δ as a selection criterion in barley breeding in Mediterranean regions. They also encourage the study of the genetics of Δ and the identification of molecular markers linked to its variation in available progenies derived from crosses between the genotypes used in the present paper.     

The borders within: Mobility and enclosure in the Riau Islands1

Abstract: The border studies literature makes a strong case against claims for unfettered transnationalism and ‘borderlessness’ in our ‘globalising world’. However, its focus on movement across borders means that it fails to address bordering practices that occur within the nation‐state as a result of transnational activity. In this paper, we extend Cunningham and Heyman’s concepts ‘enclosure’ and ‘mobility’ to confront the different layers of bordering (both physical and non‐physical) that have occurred in Indonesia’s Riau Islands since they became part of the Indonesia–Malaysia–Singapore Growth Triangle.     

一氧化氮对铜、镉胁迫下平邑甜茶幼苗活性氧代谢的影响

利用一氧化氮供体硝普纳（sodium nitroprusside,SNP）,研究了一氧化氮对铜、镉胁迫下平邑甜茶幼苗的活性氧代谢的影响。结果表明：在200μM的CuCl2或CdCl2处理下,25～200uM的SNP能够提高平邑甜茶幼苗根系和叶片的SOD,POD活性,降低根系和叶片的超氧阴离子（O-2）产生速率及丙二醛（MDA）含量,表明适当浓度的一氧化氮可以通过提高部分抗氧化酶活性来缓解铜、镉胁迫对平邑甜茶幼苗的伤害。     

A Dominant Inhibitor Gene Inhibits the Expression of Ht2 against Exserohilum turcicum Race 2 in Corn Inbred Lines Related to B14

The purpose of this study was to elucidate the genetic cause for the lack of express ion of the gene Ht2 against Exserohilum turcicum race 2 on certain genetic backgrounds related to the inbred line B14. Two such inbreds (A635Rp and B59), susceptible to this pathogen were crossed onto the inbred Oh43—-Ht2Ht2. The following generations: F₁, F₂, F₃, F₄, backcrosses to both parents, selfings of the backcrosses, in addition to the parent lines, were evaluated for Ht2 expression in this study. Plants of each generation were inoculated with E. turcicum race 2 and evaluated for the expression of the chlorotic-lesion resistance determined by the gene Ht2. In spite of the reported dominance of Ht2 on some genetic backgrounds, the F₁ generations studied here did not show Ht2 resistant lesions. The data presented herein suggest that B₁₄ and related inbred lines carry a dominant gene(I) that inhibits the expression of the Ht2 gene. Chi-square analyses of the reactions of 108 progeny families studied supported this hypothesis.