杂交中稻强再生力品种的冠层特征研究

本文以19个杂交中稻品种为材料,研究了杂交中稻强再生力品种的冠层特征.结果表明:杂交中稻品种间再生力取决于头季稻的叶粒比,强再生力品种头季稻单位颖花的绿叶面积占有量大,其光合产物满足头季稻高产之后剩余量较多,为再生稻高产提供了重要的物质基础.头季稻品种间着粒数分别与其单位颖花的绿叶面积占有量及再生力呈极显著     

Characterization of the interspecific cross Cicer anetinum L. ×C. judaicum (Boiss)

An interspecific cross involving Cicer anetinum L. and C. judaicum (Boiss) No. 182 was established. The F₁ could be distinguished from the parents by its prostrate growth habit at the seedling stage and through isozyme patterns for peroxidases and esterases. The inheritance of PRX-3 was found to be relatively simple and behaved as a monomer. Meiotic studies indicated the occurrence of six bivalents and four uni-valents in about 6% of F₁ PMC's at metaphase I, but normal 8–8 chromosomal distribution in anaphase I, indicating near complete homology. The F₁ hybrid was characterized for three morphological and six agronomical characters. A large F₂ was studied for secondary branches per plant, 100-seed weight (g), pods per plant, and grain yield per plant (g). Distributions of F₂ for pod number and grain yield displayed high C.V. and were highly skewed in a positive direction. F₂ recombinants were isolated with a very large number of secondary branches and a high pod number and yield. Such wide variability is not normally encountered in intevarietal crosses.     

水稻茎叶形态性状的简化三重测交分析

以H1459和乐一为测验系L_1和L_2,分别与泸红早等22个早籼品种进行简化三重测交(sTTC),考查了12个茎叶形态性状。其中,剑叶宽、倒2叶宽、倒3叶宽,倒2节间长和基部节间粗在两个测验系中表现为极端类型,倒3叶长和剑叶夹角在两个测验系间可能存在由于同效基因分散分布引起的真实遗传差异。对上述7个性状的遗传分析表明,基部节间粗     

起垄栽培对不同基因型冬小麦生理特性及子粒蛋白质含量的影响

以3个不同基因型冬小麦品种为材料，研究了起垄栽培对冬小麦生理特性及子粒蛋白质含量的影响，结果表明，起垄栽培可以提高灌浆初期小麦旗叶及子粒中游离氨基酸含量，提高灌浆后期旗叶硝酸还原酶活性和子粒蛋白质含量，但不同基因型品种之间存在差异。起垄栽培可以显著提高藁麦8901和郑麦975子粒蛋白质含量，而对弱筋品种豫麦50号影响不显著。     

Variation among and within Italian alfalfa ecotypes by means of bio-agronomic characters and amplified fragment length polymorphism analyses

Three accessions, corresponding to different ‘foundation’ farms, of each of the alfalfa (lucerne) Italian ecotypes ‘Vogherese’ and ‘Marem‐mano’, and two varieties were studied in order to evaluate: (1) the among‐ and within‐ecotype variation; and (2) the possibility of distinguishing the populations by means of bio‐agronomic characters and molecular markers (amplified fragment length polymorphisms, AFLPs). The two ecotypes could be distinguished by the differences in persistency after 15 cuttings in 3 years cultivation and by the seasonal distribution of the dry matter yield. Within‐ecotype variation was always of minor importance as compared with the among‐ecotype differences. The AFLP analyses generated 20 polymorphic fragments in ‘bulk’ samples: none was able to distinguish the two ecotypes, while variety‐specific fragments were found. The same analysis on an individual plant basis (485 polymorphic fragments) confirmed the absence of differences among ecotypes, while 10% of the total variance was attributable to variation among accessions within ecotype. The results of the analyses using agronomic traits and molecular markers are discussed in relation to the possibility of ecotype identification.     

Breeding for resistance to yellow disease of hyacinths. II. Influence of flowering time,leaf characters,stomata and chromosome number on the degree of resistance

Summary Analysis of an incomplete diallel design with 14 hyacinth cultivars and 4 wild accessions of Hyacinthus orientalis showed a significant GCA component for resistance to yellow disease. The late flowering hyacinth cultivars King of the Blues and Marconi and the early flowering Hyacinthus orientalis 70129 were found to be the best combiners for yellow disease resistance. Within a cultivar, the degree of earliness itself was not associated with the degree of resistance. Correlation coefficients of leaf characters and degree of resistance showed that hyacinths with short and/or narrow leaves are generally more resistant than those with long and/or broad leaves. Tetraploid cultivars with few, large stomata tend to be susceptible, diploid ones with many small stomata tend to be the more resistant.     

Partial resistance in lettuce to downy mildew (Bremia lactucae). 1. Search for partially resistant genotypes and the influence of certain plant characters and environments on the resistance level

Summary In three bicyclic inoculation experiments in the field 756 genotypes from the IVT Lactuca gene bank were screened for differences in partial resistance against Bremia lactucae. Significant differences between genotypes were found. No linkage was found between the presence or absence of R-genes and partial resistance nor was there a clear relationship between plant characters such as size, erectness and lettuce type and resistance level. Comparison of test results for genotypes which were tested twice and in different years and/or environments revealed a rather good relationship. So no clear genotype × environment interactions for resistance level were found. Results imply that the bicyclic inoculation experiments are useful to determine levels of partial resistance.     

Morphological and molecular diversity of Nordic oat through one hundred years of breeding

Summary Genetic diversity in microsatellites and development of agronomical characters in Nordic oat cultivars (Avena sativa) from the 20th century, ranging from landraces to new cultivars, were studied. A clear development in agronomical characters has taken place in this period: Straw length has been reduced, harvest index has increased and heading date has declined. The persistent oat breeding effort in the northern part of the region was indicated by the data, since cultivars from this region showed higher harvest index. Also adaptation to shorter summers was apparent in cultivars from the most northern part of the area. When comparing cultivars released after 1940 to the landraces, the loss of diversity revealed for the agronomical characters was also indicated by the molecular data. This indicates that a more general loss of diversity has taken place in the period, possibly due to random factors during the breeding process (bottleneck effect). The reduction in diversity revealed by recent cultivars at an agronomical as well as a molecular level emphasises the importance of implementing a conservation strategy for older material in order to secure genetic diversity for future oat breeding efforts.     

不同抗源基因棉主要性状杂种优势及差异分析

主要对三种类型转基因抗虫棉包括国产单价、国产双价及美国单价抗虫棉杂种F1代主要性状的杂种优势及差异进行了分析。结果表明:在产量与产量性状方面,F1霜前皮棉产量、子棉产量、铃重和衣分具有明显的正向优势,其优势组合率分别为95.80%、83.33%、95.45%和87.50%,竞争优势(CH%)分别为27.65%、14.26%、13.13%和11.95%。在农艺性状方面,株高具有明显的正向优势,其竞争优势值为22.64%,而果枝数和单株结铃数优势不明显,其竞争优势分别为2.78%和 7.33%。在纤维品质方面,2.5%跨长、整齐度、比强度均为负优势,伸长率和麦克隆值均为正向优势。不同转基因抗虫棉相比,以sGK321双价抗虫棉为亲本的杂种平均竞争优势CH%最高,以GK12为抗虫亲本的组合伸长率竞争优势最高,以晋棉26为抗虫亲本的组合比强度竞争优势最高,以新棉33B为抗虫亲本的组合2.5%跨长、整齐度和麦克隆值的竞争优势最高。     

Variability and early selection on the seedling stage for agronomic traits in progenies from olive crosses

Yield per tree, ripening date and oil content components (fruit fresh weight, flesh moisture, flesh/stone ratio both on fresh and dry weight basis, flesh and fruit oil content on dry weight basis) have been studied during 3 years in seedlings from crosses among the olive cultivars ‘Arbequina’, ‘Frantoio’ and ‘Picual’. Genetic and environmental variances and year‐to‐year consistency of data were estimated. Most of the traits evaluated showed a range of variability as large or even larger than either the range observed in a random sample of cultivars from the World Olive Germplasm Bank of Cordoba or the range reported in the evaluation of olive cultivars collections. Between‐years correlation coefficients showed that for a character such as oil content the values obtained in the first year could be reliable indicators of the values obtained in following years. Observations over 2 years may be required for characters such as fruit weight or flesh/stone ratio on a fresh weight basis and even more than 2 years may be required to estimate yield per tree.