葡萄糖氧化酶基因在棉花中的高效转化——转基因再生棉株的获得

利用农杆菌介导法把葡萄糖氧化酶基因转移到棉花中 ,获得了再生植株 ,并对影响棉花愈伤组织分化和植株再生的因素作了探讨。离体分子检测表明 ,外源基因已整合到棉花基因组中     

五个澳洲野生棉种的核型研究

对斯特提棉（Ｇ．ｓｔｕｒｔｉａｎｕｍ）、南岱华棉（Ｇ．ｎａｎｄｅｗａｒｅｎｓｅ）、澳洲棉（Ｇ．ａｕｓｔｒａｌｅ）、纳尔逊氏棉（Ｇ．ｎｅｌｓｏｎｉ）和比克氏棉（Ｇ．ｂｉｃｋｉ）五个澳洲野生棉种的染色体核型进行了分析研究。结果表明，五个澳洲野生棉种的核型比较相似，均有两对随体染色体，种间的核型重合率均大于８５％，其中斯特提棉与南岱华棉、澳洲棉与纳尔逊氏棉，及其比克氏棉与澳洲棉或纳尔逊氏棉之间的核型重合率大于９０％。此外，本文对比克氏棉的系统发育和染色体组划分等问题进行了讨论。     

基于生理发育时间的棉花生育期模拟模型

棉花生育期模拟是研究棉花生长与环境因子关系的重要内容。通过分析春播中(中早)熟常规棉、中(中早)熟转基因抗虫棉和夏播早熟短季棉三种类型16个品种(系)的生育期与环境因素的动态关系,建立了以棉花生理发育时间(PDT)为基础的棉花生育期模拟模型。模型考虑了热效应、光周期效应、品种早熟性及地膜覆盖地积温对气积温的补偿效应。利用不同年份、生态区、基因型品种、栽培措施的试验资料对模型进行了检验,结果表明不同品种生育期模拟值与观测值的符合度较好,各生育进程的RMSE在1.4～4.9d。模型既有较强的机理性,又有较好的适用性。     

陆地棉与三裂棉、斯特提棉和A111种间杂种F1的形态与细胞学

本文研究了TM-1×三裂棉、江苏棉1号×斯特提棉、泗棉2号×Alll 3个种间杂种F_1的主要形态特征及花粉母细胞减数分裂中期Ⅰ的染色体行为。3个种间杂种F_1的花器官性状大多趋向于父本野生棉,如花冠颜色、花心等;营养器官大多趋向于中间型,如叶色、叶形等。杂种F_1均表现高度不育。减数分裂中期Ⅰ的染色体构型依次为:13.73Ⅰ 12.52Ⅱ 0.03Ⅲ 0.04Ⅳ,28.03Ⅰ 5.38Ⅱ 0.07Ⅲ和33.26Ⅰ 2.87Ⅱ;其染色体组亲和性指数分别为0.9715、0.4192和0.2208。这一结果表明:(1)陆地棉与三裂棉的亲缘关系较近,与斯特提棉的亲缘关系较远,与Alll的亲缘关系更远;(2)泅棉2号×Alll的F_1染色体数为2n=3x=39,其染色体数x=13与棉属相同,其次因Alll原产于澳大利亚,形态上与纳尔逊氏棉、澳洲棉比较接近,因此推测它可能属于棉属的C染色体组种。     

Genetic analysis of presence and absence of lint and fuzz in cotton

Cotton fibre mutants that were fuzzless and/or lintless were crossed with each other and a normal genotype (fuzzy, linted) to produce F₂ and BC₁ generations. F₂ segregation ratios from the cross of fuzzless‐lintless × fuzzy‐linted, for fuzzy‐linted, fuzzless‐linted and fuzzless‐lintless were 45 : 15 : 4. From the cross of fuzzless‐lintless × fuzzy‐linted, the F₂ segregation ratios were 9 : 39 : 16 whereas the BC₁F₁ segregation ratios from the F₁ backcrossed to fuzzless‐lintless were 1 : 3 : 4. These data suggest that the presence or absence of lint and fuzz are controlled by the interaction of four gene loci on non‐homologous chromosomes. We designate these loci as N₁, N₂, Li₃ and Li₄, where N₁ N₁ confers the presence of fuzzy, N₂N₂ confers inhibition of fuzzy initiation and development, and duplicate gene pairs, Li₃Li₃ and Li₄Li₄, determine the presence of lint. Homozygosity for li₃li₃ and li₄li₄ might also inhibit fuzz from development. In other words, they were recessive epistatic to fuzz genes.     

棉属野生棉与栽培棉种间杂交新种质创造研究

棉属(Gpssypium)野生资源具有的抗病、虫,抗旱及优质纤维等遗传特性,通过种间杂交可转育到栽培棉,以丰富和改善现有栽培棉品种的遗传特性或创造新的优异种质材料供育种利用。本文报道用23个棉属的野生种与4个栽培种的品种杂交,获得不同世代的47个组合杂种,并从一部分杂种后代培育出一批抗病、虫,抗旱和纤维高强优质等遗传特性的新种质。同时研究了有关种间杂交的不亲和性、杂种F_1的遗传性状以及细胞遗传学、胚胎学等问题。     

T1 locus in cotton is the candidate gene affecting lint percentage, fiber quality and spiny bollworm (Earias spp.) resistance

A genetic linkage map of chromosome 6 was constructed by using 270 recombinant inbred lines originated from an upland cotton cross (Yumian 1 × T586) F₂ population. The genetic map included one morphological (T₁) and 18 SSR loci, covering 96.2 cM with an average distance of 5.34 cM between two markers. Based on composite interval mapping (CIM), QTL(s) affecting lint percentage, fiber length, fiber length uniformity, fiber strength and spiny bollworm resistance (Earias spp.) were identified in the t₁ locus region on chromosome 6. The allele(s) originating from T586 of QTLs controlling lint percentage increased the trait phenotypic value while the alleles originating from Yumian 1 of QTLs affecting fiber length, fiber length uniformity, fiber strength and spiny bollworm resistance increased the trait phenotypic value.     

Dry matter accumulation and partitioning in cotton (<Emphasis Type="Italic">Gossypium hirsutum</Emphasis> L.) as influenced by potassium fertilization

The effect of potassium (K) supply on dry matter accumulation and partitioning of biomass between different among parts of cotton (Gossypium hirsutum L.) was determined under irrigated conditions. The treatments were four cotton cultivars (CIM-448, CIM-1100, Karishma, and S-12), four K rates (0, 62.5, 125, and 250 kg K ha⁻¹), and two K-fertilizer sources (K₂SO₄, KCl). Sequential harvests were collected at four stages of growth, viz first flower, peak flowering, first boll split, and maturity. The dry weights (DW) of vegetative and reproductive organs were determined. Maximum total DW was obtained at 125 days after planting, and then it declined because of leaf senescence at maturity. Cultivars differed significantly among themselves in the production of total DW and its partitioning between different organs. The addition of K fertilizer increased DW substantially at various stages of growth. Potassium fertilizer stimulated cotton plant to translocate resources towards reproductive organs rather than vegetative organs. Crop receiving 250 kg K ha⁻¹ allocated 77% more dry matter into reproductive organs. The K-sources produced a little effect on the allocation of DW in various parts of the plant. Maximum reproductive–vegetative ratio (RVR) was maintained by cv CIM-448 and minimum in cv CIM-1100. Data showed that a shift in DW allocation into reproductive organs was dependent upon sustained supply of K⁺ throughout the season. There were positive significant correlations (0.86, 0.71, and 0.90) between seed cotton yield and total DW, vegetative DW, and reproductive DW, respectively.     

Changes in photosynthesis and antioxidant metabolism of cotton (Gossypium hirsutum L.) plants in response to manganese stress

ABSTRACT

This study aimed to assess the physiological and biochemical responses of cotton plants to manganese (Mn²⁺) nutrition. Four cotton genotypes (G1 – TMG 47; G2 – FM 975 WS; G3 – TMG 11 WS and G4 – IMA 8405 GLT) were grown in nutrient solution under two Mn²⁺ concentrations (2 and 200 µmol L^?1) for 10 days. No visible symptoms of Mn²⁺ toxicity were observed in the genotypes tested. All genotypes showed a marked increase in leaf chlorophylls, pheophytins, carotenoids, sucrose and total sugars concentration in response to high Mn²⁺ in a nutrient solution. However, the net photosynthetic rate, stomatal conductance, internal carbon dioxide concentration and transpiration decreased in genotypes G1 and G2 growing under 200 µmol L^?1. Antioxidant enzymes such as superoxide dismutase (SOD), ascorbate peroxidase (APX) and glutathione reductase (GR) activities increased in genotypes G1, G3 and G4. Cotton genotypes showed an increased leaf antioxidant and sugar metabolism as a possible strategy to mitigate oxidative stress. The decrease in the net photosynthetic rate and stomatal conductance; the increased antioxidant enzymes activities (SOD, APX and GR); and the increase in leaf sucrose and total sugar concentration were the main physiological and biochemical responses in cotton plants to Mn²⁺ stress.