Herbage yield and quality of Gliricidia sepium under different cutting heights and defoliation frequencies

The browse shrub Gliricidia sepium, introduced into the subhumid zone of Nigeria to serve as a supplementary-forage source for ruminant during the dry season, has the undesirable characteristic of shedding its leaves during its flowering phase which coincides with the early dry season. This report relates a management practice undertaken to maintain G. sepium in vegetative growth through the dry season. Evaluation was undertaken on the influence of cutting to different heights and defoliation at different frequencies. Eight different accessions of the species were involved in the study. Cutting generally ensured vegetative growth during the early dry season, with greater shoot development observed at a cutting height of 0.7 m than at two lower heights. Under the double harvest regime, dry matter yield was generally highest at first harvest and significantly (P < 0.05) so at a cutting height of 0.3 m than at 0.5 or 0.7 m. Accession HYB yielded more dry matter than three other accessions harvested once. Cutting to 0.7 m yielded more leaves than cutting at lower heights. The foliage contained adequate levels of organic matter, crude protein and the minerals, Ca and P while the accession HYB consistently maintained a higher dry matter yield than the other accessions.     

不同高粱种质对污染土壤中重金属吸收的研究

利用重金属含量较高的污水污染土壤,以未污染土壤作对照,种植8个甜高粱品种、2个饲用高粱品种和1个粒用高粱品种,检测8种重金属在高粱植物体内不同器官的含量,以研究不同高粱种质对重金属的吸收特性。结果表明:甜高粱对汞(Hg)、镉(Cd)、锰(Mn)和锌(Zn)的吸收在两种土壤间差异显著,对钴(Co)、铬(Cr)、铅(Pb)和铜(Cu)的吸收差异不显著。Mn在甜高粱体内含量表现为未污染土壤高于污染土壤;而Zn含量在不同器官之间存在差异,未污染土壤叶中含量远高于穗,穗中含量远高于茎和根。不同重金属在甜高粱体内的储存部位不同,污染土壤上Hg、Cd、Co、Cr和Zn在根中积累量较高,Cu、Mn和Pb在穗中的积累量较高。甜高粱、饲用高粱和粒用高粱对重金属的吸收、运输及储存在品种之间差异较大,同一品种对不同重金属的吸收也存在差异。饲用高粱表现为叶部对Cr和Zn的储存量较高,而粒用高粱‘晋中0823’则显示了茎对多种重金属的储存能力。高粱根对土壤中重金属的富集系数较高,为0.02(Pb)~0.23(Cd),转移系数变幅为0.21(Co)~3.42(Pb)。对同一种重金属的吸收量品种间差异较大,甜高粱‘西蒙’根对Co、Cr、Cu、Mn、Pb和Zn具有高富集系数,粒用高粱‘晋中0823’茎对Hg、Cd、Mn、Pb和Zn富集系数较高。高粱对重金属的吸收能力与转移能力不同步,甜高粱‘绿能1号’具有对多种重金属的高转移能力,粒用高粱‘晋中0823’只对Zn有较高的转移能力。因此本文认为甜高粱对不同重金属的吸收和转移有选择性。对Zn吸收并转移到地上部后,首先储存在叶和穗中,当吸收量足够大时,茎和根也成为储存器官;对Mn的吸收与其他重金属的吸收存在竞争作用,Hg吸收后很少向地上部转移;而对Cu、Mn和Pb吸收后在穗部的储存量较大。饲用高粱与甜高粱相比对重金属的吸收未显示明显的不同,甜高粱‘西蒙’根对多种重金属具有强储存能力,而粒用高粱‘晋中0823’的茎秆显示了比甜高粱更强的储存能力,甜高粱‘绿能1号’对多种重金属的转移能力较强。所以,选择富集和转移能力均强的高粱品种能更有效地吸收土壤中的重金属,达到修复污染土壤的目的。     

芝麻茎点枯病抗性关联分析及抗病载体材料挖掘

【目的】利用自然群体进行芝麻茎点枯病抗性相关分子标记开发研究,挖掘优异抗病载体材料。【方法】利用79对EST-SSR、SRAP和AFLP引物对216份芝麻核心种质进行了基因组扫描,并于2009-2011年连续3年对供试群体抗病性进行鉴定,在此基础上采用标记-性状关联分析法进行芝麻茎点枯病抗性相关基因定位。【结果】扩增获得608条多态性条带,遗传结构分析表明该群体由2个亚群组成,利用GLM（Q）和MLM（Q+K）模型通过关联分析共检测到43个标记同时与供试群体两年或三年茎点枯病病情指数（DI）显著关联,对表型变异解释率在1.82%-9.46%,两种模型检测到的相同标记有3个,其中,标记M7E6-1连续三年均能被2种模型检测到,优选出10份对茎点枯病抗性稳定的载体材料,43个关联标记在10份载体材料中的符合率变化于60%-100%,平均符合率92.09%。【结论】供试群体由2个亚群组成,亚群的划分与材料的地理来源没有必然联系,关联分析检测到43个与DI稳定显著关联的标记,供试群体抗病性变异较丰富,从中优选出10份稳定抗病载体材料。     

余甘子各器官总黄酮含量分析

分析比较了余甘子各器官之间、不同余甘子品种之间以及与野生资源之间的总黄酮含量。结果表明,黄酮类化合物普遍存在于余甘子各器官中,以叶片与果实中居多,枝、根中含量较低：皇帝甘枝条的总黄酮含量高于玻璃甘枝条。粉甘、蓝丰、秋白这3个品种的果实总黄酮含量差异显著。3个野生资源单株总黄酮含量差异显著,野生余甘子果实总黄酮含量高于栽培品种。     

Tissue distribution and changes in dopamine during development and stress responses in Malus germplasm

Dopamine is a catecholamine and an anti-oxidant which functions in responses to stress and it interacts with plant hormones to mediate plant development. At present, there are few studies on the functions of dopamine in apple. This study developed a method for dopamine determination which was used to analyze dopamine in Malus germplasm, in order to clarify the tissue distribution, developmental changes, diurnal variations, and stress responses in apple trees. First, the proposed method was verif...     

以方便读者为前提认识和使用辅助区分号

论述了如何从读者检索的意愿和习惯出发,合理使用辅助区分号,使馆藏图书的体系更加科学合理。     

基于外借分析的入藏结构调整

对肇庆学院图书馆近4年的外借资料和近2年的新书入藏结构进行了统计分析,获得了调整馆藏文献资源结构的依据,进而提出实现最佳馆藏的比例结构和相应改进措施,有助于提高馆藏资源质量。     

Genetics of angular leaf spot resistance in the Andean common bean accession G5686 and identification of markers linked to the resistance genes

Angular leaf spot (ALS), caused by the fungus Phaeoisariopsis griseola is an economically important and widely distributed disease of common bean. Due to the co-evolution of P. griseola with the large and small seeded bean gene pools, stacking Andean and Mesoamerican resistance genes is a strategy most likely to provide lasting resistance to ALS disease. This strategy requires identification and characterization of effective Andean and Mesoamerican resistance genes, and the development of molecular markers linked to these genes. This study was conducted to elucidate the genetics of ALS resistance in the Andean accession G5686 using an F₂ population derived from a G5686 × Sprite cross. Segregation analysis revealed that three dominant and complementary genes conditioned resistance of G5686 to P. griseola pathotype 31-0. Three microsatellite markers, Pv-ag004, Pv-at007 and Pv-ctt001 segregated in coupling phase with the resistance genes in G5686. Microsatellites Pv-ag004 and Pv-ctt001, located on opposite ends of linkage group B04 segregated with resistance genes Phg _G5686A , Phg _G5686B at 0.0 and 17.1 cM, respectively, while marker Pv-at007, localized on linkage group B09 segregated with resistance gene Phg _G5686C at 12.1 cM. Parental surveys showed that these markers were polymorphic in Andean and Mesoamerican backgrounds. The usefulness of G5686 ALS resistance genes in managing the ALS disease, and the potential utility of identified molecular markers for marker assisted breeding are discussed.     

陕西豌豆种质资源形态性状遗传多样性分析

【目的】阐明陕西豌豆种质(含省内及来自省外的资源)的形态特点,揭示其遗传结构、遗传多样性的差异,为陕西豌豆资源的利用和育种提供理论依据。【方法】根据生育期、花色、粒色和粒形的不同选取100份种质,分析陕西豌豆及省外豌豆资源生育期、株高、单株荚数、单荚粒数、百粒质量、单株产量、花色、粒形、粒色9个形态性状的分布特点,计算各性状在不同群体中的遗传多样性、遗传距离,并对选取的100份材料进行聚类分析,在主成分分析的基础上绘制品种分布的三维散点图。【结果】陕西豌豆以紫花、麻粒和白粒、圆粒为主,从陕北到陕南皱粒比例增加,粒色类型更加丰富。省外豌豆以白花、白粒、圆粒为主,但皱粒豌豆的比例明显高于陕西豌豆。与陕西豌豆相比,省外资源生育期短,株高低,单株荚数、百粒质量、单株产量高。陕西以及陕南豌豆的平均遗传多样性高于省外群体,省内不同地区间的平均遗传多样性指数以陕南为高,其次是陕北、关中。省外群体的平均遗传距离大于省内群体。省内群体的平均遗传距离以陕南为最大,然后依次是关中、陕北;省内不同群体间的平均遗传距离,以陕南-关中为最大,然后依次是陕南-陕北、关中-陕北。聚类分析将供试100份种质分成2类,第Ⅰ类主要由陕南、省外品种组成,第Ⅱ类主要由关中、陕北组成。聚类和三维散点图结果显示,陕南品种分布最为广泛,其次分别是省外、关中、陕北的品种,不同地区的品种没有形成相对独立的区域,而是相互穿插,界限模糊。【结论】省外资源的农艺性状优于省内资源,是陕西豌豆资源的重要补充。陕西豌豆的遗传多样性以及遗传距离与品种的地理来源相关不明显。     

Variation among maize (Zea mays L.) accessions of Bendel State,Nigeria. Multivariate analysis of agronomic data

Summary Two multivariate techniques were used to characterize 30 maize accessions collected from three ecological zones of Bendel State, Nigeria. Differentiation of the 30 accessions into five distinct groups was achieved with the unweighted variable group method of the average linkage cluster analysis of 34 agronomic characters. Four of the taxonomic groups contained at least three accessions each, while a fifth group contained only one. The single accession contained in the fifth group was characterised by very early maturity, deeply pigmented leaves and ear husks and short statured plants. Clustering of the accessions into different phenetic groups followed substantially along geographical and traditionally trading routes. A few cases of overlapping of accessions from different geographical locations were obtained.Principal component analysis revealed that days to 50% tasseling and silking, number of nodes/plant, ear length, ear weight, leaf width, and kernel colour were the principal discriminatory characters that differentiated the accessions. Sixty-four percent of the total variation among the 34 characters were accounted for by the first five principal components while the first and second components accounted for 26 and 14 respectively.