RFLP characterization of Indian Musa germplasm for clonal identification and classification

Summary Nineteen single-copy clones isolated from a PstI genomic library (cv. Maiden Plantain), and eight Vigna chloroplast DNA clones were used to probe total genomic DNA digests of 57 genotypes of Musa from India. The 19 genomic clones detected a total of 107 polymorphisms among the 57 genotypes. Principal coordinates and phenetic analyses of these data placed cultivars and species into distinct groups that were in general agreement with a previously published RAPD-based classification of these same plant materials. The 107 polymorphisms were sufficient to differentiate each clone from every other clone. Heterologous Vigna chloroplast DNA probes were used to characterize the cytoplasm of Musa cultivars and species. PCO analysis of these RFLPs were detected both within and between the generally recognized genome groups, indicating multiple hybridization pathways in the origin of hybrid clones. Data presented demonstrate that RFLPs are sufficiently abundant to classify Musa germplasm and that genetic relationships among Musa cultivars, based upon RFLP data, are in general agreement with relationships determined by analysis of morphology and RAPDs.     

Wide mapping of a T-DNA insertion site in oilseed rape using bulk segregant analysis and comparative mapping

Doubled haploid oilseed rape lines segregating for a transgene inducing herbicide resistance (bar gene) were investigated for the wide mapping of the T-DNA insertion site. Bulk segregant analysis using presence/absence and intensity polymorphisms between the bulks, as well as comparative mapping with a linkage group deriving from another cross, led to the identification of 11 random amplified polymorphic DNA (RAPD) markers tightly or loosely linked to the bar gene. Ten RAPD loci out of 11 were located on the same side of the bar locus, strongly suggesting that the T-DNA integrated in a telomeric or subtelomeric position. The eleventh RAPD marker exhibited a strong segregation distortion, which could be the result of a heteroduplex formation. Comparison of the linkage groups obtained from the two crosses showed different recombination rates between markers, possibly reflecting differences in parental genetic backgrounds. Consequences and potential applications in transgene dispersal safety assessment studies are discussed.     

The study of introgressive lines of Triticum aestivum × Aegilops speltoides by in situ and SSR analyses

Fluorescence in situ hybridization (FISH) with a genome‐specific repeat, Spelt1, and wheat simple sequence repeat (SSR) markers were used to analyse the chromosome constitution of two Triticum aestivum×Aegilops speltoides introgressive lines. The lines 170/98i and 178/98i carried one and two subtelomeric regions of Ae. speltoides (per haploid genome), respectively, marked by Spelt1 repeats according to FISH data. SSR analysis detected homoeologous substitution of wheat chromosome 7D with Ae. speltoides chromosome 7S in the lines 178/98i and 170/98i as well as the assumed terminal translocation in the short arm of chromosome 3A in the line 178/98i. Anthocyanin pigmentation of the coleoptiles was found in the lines 170/98i and 178/98i and resulted from the 7S (7D) substitution. It was demonstrated that Spelt1 could be effectively used for the rapid identification (without DNA isolation) of terminal translocations of T. aestivum×Ae. speltoides introgressive lines as well as for further analysis of the stability of the hybrid plants.     

Analysis of spaced-plant and micro-plot performance for yield-related traits in octoploid and hexaploid primary triticales

Summary Twenty-nine primary triticales (x Triticosecale Wittmack), derived from homozygous, uniform wheat and rye inbreds, were evaluated (i) to assess wheat, rye and interaction effects for yield-related characters, (ii) to estimate correlations between these characters, and (iii) to investigate the possibility of predicting micro-plot performance from early spaced-plant tests. The triticales (12 octoploid, 17 hexaploid) were tested under space-planting and in micro-plots in three-replicate, randomized block designs in 1983 and 1984, respectively. In general, hexaploid triticales performed significantly better than octoploids. Strong wheat and wheat x rye interaction effects were found, making it difficult to predict the performance of primary triticales from their constituent parental genotypes. At both ploidy levels under space-planting kernel weight per spike showed significant positive correlations with spikelets per spike, kernels per spikelet, and 1000-kernel weight. No significant associations were detected between spaced-plant and micro-plot performance for octoploids, indicating severe disorders at this ploidy level. In hexaploid triticales spikes per plant, kernel weight per spike, and kernels per spikelet observed in spaced-plants appeared to be useful indicators of grain yield in micro-plots.     

同核异质滇I型粳稻不育系及其保持系的光合特性

滇I型不育系和保持系是我国粳稻杂种优势利用最主要的技术体系之一。本研究利用Li-6400便携式光合测定系统测定了79对滇I型同核异质粳稻不育系及保持系上三叶的净光合速率(P_n)、气孔导度(G_s)、胞间CO₂ 浓度(C_i)、蒸腾速率(T_r)、水分利用效率(WUE)、气孔限制值(L_s)和叶绿素相对含量(SPAD)。结果表明,不育系间及保持系间的光合参数在3个叶位上都达到了极显著水平,基因型间的这种显著差异为高光效育种提供了宝贵的遗传基础。同一叶位上不育系与保持系间的光合参数具有显著的正相关。除SPAD值外,其他光合参数值在不育系与保持系间没有显著差异,但不育系的SPAD值显著大于保持系。叶绿素相对含量不是粳稻提高光合作用的限制因子;滇I型细胞质对光合作用没有负效应;利用滇I型细胞质转育的不育系的叶绿素含量很可能有所提高。基于剑叶光合参数值对保持系及不育系的聚类,不育系和保持系可分别分为高和较低光合速率的类型。本研究为滇I型不育系的高光效育种提供了理论基础,也可作为杂交粳稻高光效的理论参考。     

热带、亚热带玉米自交系与温带自交系遗传关系研究

以 9个热带、亚热带玉米自交系和 5个代表中国温带主要杂优群的自交系为材料 ,利用SSR分子标记技术和NC -Ⅱ遗传设计的田间试验方法 ,研究了它们之间的遗传关系。结果表明 ,温热杂交组合掖 478×CML31 0、Mo1 7×CML1 0、黄早 4×CML1 0 7、旅 9×CML31 0、自330×CML31 2产量特殊配合力较高 ;根据SSR标记遗传多态性结果将供试自交系分为 6个杂优类群 :第 1类群包括CML1 0、CML2 65 ,第 2类群包括CML2 7、CML96、CML2 95、Mo1 7,第3类群包括CML32 3、黄早 4 ,第 4类群包括CML31 0、CML31 2、自 330、丹 340 ,第 5类群包括CML1 0 7,第 6类群包括掖 478;SSR标记的分类结果与产量配合力及系谱分析结果基本一致     

人工合成的十个优良小麦种质系的细胞学和性状特点的研究

本试验对从八倍体小偃麦与普遍小麦的杂种后代中选出的10个优良小麦种质系,进行了细胞学和田间试验鉴定。结果表明,在这10个小麦种质系中,其中有2个品系为单体异附加系,1个品系为双单体异附加系,2个品系为双体异附加系。有5个品系染色体数目与普通小麦相同,但具有偃麦草的某些特点,细胞学上具有异常行为,它们可能为新的次生六倍体小麦。这些小麦种质系中,有的综合性状较好,具有较好的丰产性能,有希望在生产上直接加以利用;有的虽然综合表现欠佳,但具有突出特点,可作为种质材料在育种上利用。     

培育水稻主要产量性状杂优近等基因系探讨

为了阐明水稻杂种优势的遗传基础,探寻水稻杂种优势研究的新方法。用有代表性的6个保持系和8个恢复系为父本,以滇粳优1号和明恢63为母本进行不完全双列杂交。对各主要产量性状进行配合力及杂种优势分析。结果表明,所选用亲本的各产量性状具有不同的一般配合力表现;杂交F1组合的各产量性状特殊配合力有明显差异;F1代各组合的各产量性状杂种优势差异显著。提出根据主要产量性状的杂种优势和特殊配合力表现筛选出产量性状杂种优势明显的组合针对特定的产量性状进行连续选择回交,培育产量性状杂种优势近等基因系,将杂种优势这一复杂数量性状分解为单个孟得尔因子来研究,进而研究水稻杂种优势的遗传机理。这一方法必要而可行,所培育的各产量性状杂种优势近等基因系对育种工作也有重要的利用价值。     

品种稳定性参数在番茄品系品质试验中的应用分析

采用测度基因型与环境互作的Eerhert和Russell分析模型对7个番茄品系进行了果实营养品质性状[维生素C、有机酸、可溶性固形物(TSS)含量和糖酸比]上品系稳定性(可预测性和环境敏感性)的分析。结果表明,2个太空诱变品系YH02-2和YH02-6表现出较好的稳定性,品质也较为优良,可作为优良的品系大面积推广。同时探明这7个番茄品系的营养品质中糖酸比性状不受环境干扰,表现型较真实地反映了品系的遗传特性,果实维生素C和可溶性固形物(TSS)含量性状不稳定的品系相对较多,有机酸含量性状不稳定的品系相对较少,反映出番茄果实营养品质性状遗传机制的复杂性。