Comparison between phenetic characterisation using RAPD and ISSR markers and phenotypic data of cultivated chestnut (Castanea sativa Mill.)

Patterns of phenotypic and phenetic variability in sixPortuguese cultivars of chestnut (Castanea sativa Mill.) are evaluated. Morphological characterisationwas based on the quantification of seventeen traits. Varianceanalysis showed significant differences among cultivars, and cultivar× year for all the traits studied, and trees within cultivarsshowed also some significant differences for some of themorphological variables. A significant correlation was obtainedbetween length of the leaf blade and the percentage of unisexual andandrogynic inflorescence with the effective thermal index,accumulated rainfall from April to October and from July to October,or the accumulated temperature below seven during the dormant period.Principal Component and cluster analysis were performed to group thecultivars, according to their similarity coefficients. For molecularcharacterisation, 125 RAPD and 157 ISSR polymorphic markers wereamplified using 28 and 7 primers respectively. High level ofcongruence among the two marker systems (r =90.5%) was obtained from comparison of pheneticsimilarities based on the percentage of shared fragments. ISSRmarkers revealed important advantages over RAPDs, due to a higheffective multiplex ratio (12.5 for ISSR compared with 2.2 forRAPD analysis) and reproducibility. Although morphological andmolecular results are comparable, slight differences are showed incluster analysis UPGMA dendrograms. Molecular analysis explainedhomonym situations among 'Martainha' and'Longal' cultivars in Portugal.     

山西芝麻种质资源遗传多样性分析

为了解山西芝麻种质资源遗传多样性,本研究对189份山西芝麻种质资源的10个质量性状和8个数量性状进行遗传多样性分析和聚类分析。结果表明：189份山西芝麻种质资源的表型性状存在较大的遗传差异,质量性状以主茎茸毛量的遗传多样性指数最高,为1.15,以蒴果棱数的变异系数最高,为63.88%;数量性状以节间长度的遗传多样性指数最高,为2.09,以单株产量的变异系数最高,为47.66%;通过聚类分析,将189份山西芝麻种质资源分为4个类群,类群Ⅰ可作为选育八棱、高秆品种的亲本材料,类群Ⅱ为矮秆、短节间特异材料,类群Ⅲ为高产选育目标材料,综合性状较好,可直接作为优异亲本加以利用,类群Ⅳ包含一批单花、高产特异材料。     

Variation in primitive landraces of common bean (<Emphasis Type="Italic">Phaseolus vulgaris</Emphasis> L.) from Argentina

The phenotypic variation found in four common bean (Phaseolus vulgaris L.) complex primitive landraces, among a group of accessions collected in Northwestern Argentina in several missions is described, with particular attention to the wide diversity found in some small areas. It is presented a hypothesis about the maintenance of such diversity in bean mixtures or complex primitive landraces that grow close to their wild relative. Wide diversity regarding to seed type and plant characteristics was displayed by the landraces MCM-SV (composed of 11 lines), MCM-292 (14 lines), MCM-298 (5 lines) and VAV-3716 (14 lines). Food uses of dry seed and fresh pod seemed to be more relevant than the aesthetic use although all of them were presumably considered by humans for centuries resulting in the current phenotypes of these complex primitive landraces. Additionally, some weedy types (intermediate between wild and domesticated types) were detected in the landracesMCM-292 and MCM-298. The four complex landraces described consisted of highly diverse mixtures and they could play a role in breeding to enlarge the genetic basis of domesticated bean varieties belonging to the Andean gene pool.     

Sorghums of the Sudan: analysis of regional diversity and distribution

Sorghum [Sorghum bicolor (L.) Moench] is a very important crop in the Sudan serving as a primary source of food, beverage, and total livelihood for millions of people in the country. The crop originated in the Northeast quadrant of Africa, and the Sudan is widely recognized as a major center of diversity. Although Sudanese sorghum germplasm has been assembled and stored over the last 50 years, careful analysis of this valuable germplasm has not been made. The objectives of this study were to assess phenotypic diversity and compare pattern of distribution among Sudanese sorghum landraces collected from different geographical regions. Phenotypic diversity among landraces was high, as expressed by the large range of variation for mean quantitative traits and the high (0.81) Shannon-Weaver diversity index. Landraces from Gezira-Gedarif tended to be shorter in stature, earlier in maturity and less sensitive to changes in photoperiod. They also had long, narrow and compact panicles that may result from adaptation to low rainfall and early adoption of mechanized farming practices. In contrast, taller and later maturing plant types characterized sorghums from Equatoria, most of which delayed their flowering in response to increased day-length. These sorghums included many genotypes with small and light kernels. Collections from Kassala showed a higher frequency of landraces with kernels that were more difficult to thresh. Landraces from Blue Nile tended to have greater agronomic eliteness with higher proportion of landraces with white kernels, poorly covered and that were easy to thresh. Sorghums from the Upper Nile tended to have loose panicles with poorly covered kernels that may result from adaptation to high rainfall of the Southern region. Although distinct distributions of types were represented by geographical origin, a high level of within-region diversity was present among all Sudanese sorghums.     

贵州黑马羊间性、无角、颌下髯及颈部肉垂遗传特征分析

通过实际观察、杂交试验、考察育种记录、遗传分析和适合性检验,对贵州黑马羊间性、无角、颌下髯以及颈部肉垂特征遗传规律进行了研究,同时分析和探讨了黑马羊相关遗传特征表现的基因表达方式和遗传关系.结果表明:①“无角×无角”繁殖的F1代无角羊占72.41％,有角羊占24.14％,无角间性羊占3.45％;②“有角×有角”繁殖的F1代有角羊为100％.③“有角×无角”、“无角×有角”的正反交试验,F1代无角羊占52.20％、有角羊占47.80％.④对166只19个群体的黑马羊统计,颌下有髯率为80.72％,颈部有肉垂率为19.28％;无角(P)对有角(p)呈显性,无间性(I)对间性(f)呈显性,颌下有髯对无髯呈显性,颈部有肉垂对无肉垂呈完全显性;有角山羊基因型为ppH,正常无角羊基因型为PPII、PPIi和PpII、PpIi,间性羊基因型为PPii、Ppii,且山羊间性与无角存在连锁关系.     

基于表型和基因型的藜麦种质资源遗传多样性分析

为了解和掌握青海省引进和收集藜麦种质资源的遗传背景和多样性,本研究选择11个表型性状和221对SSR引物对114份藜麦种质资源进行遗传多样性分析。结果表明,114份藜麦种质资源的11个表型性状差异极显著（P＜0.01）,变异系数范围为4.57%~87.79%,主穗直径的变异最大（87.79%）,籽粒直径的变异最小（4.57%）;遗传多样性指数范围为0.47~2.29,单株产量的遗传多样性指数最大（2.29）,茎秆长最小（0.47）。46对多态性较好的SSR引物扩增出165条多态性条带,每对引物的平均等位变异数为3.59,观测等位基因（Na）平均值为1.65,有效等位基因（Ne）平均值为1.50,Shannon’s信息指数（I）和Nei’s基因多样性指数（He）平均值分别为0.39和0.27,平均多态性比率为64.35%。通过聚类分析发现,114份藜麦种质基于表型性状和SSR分子标记的聚类结果存在一定的相似和差异,来源地相同的种质被分到了不同的类群,来源地不同的种质被分到了同一类或单独聚成一类,说明参试藜麦种质资源的表型性状和分子遗传信息多样性较丰富。     

不同土壤水分条件下断茎处理对克隆植物结缕草表型可塑性的影响

通过断茎处理,研究在不同土壤水分条件下克隆植物结缕草的水分生理整合作用对表型可塑性的影响。结果表明,在土壤水分均质和异质环境下,与断茎处理相比,保持匍匐茎的连接对结缕草的形态学指标均有促进作用;断茎处理均降低了分枝强度;在土壤水分异质和均质环境下,在结缕草克隆植株内存在水分生理整合,而且整合的方向既有从基部到梢部的向顶传输,又有从梢部向基部的向基传输,即水分传输是双向的。     

泰山赤鳞鱼苹果酸酶同工酶表型差异的研究

应用聚丙烯酰胺凝胶电泳结合生化染色方法分别对雌雄泰山赤鳞鱼10种组织中苹果酸酶同工酶酶谱进行分析。结果表明,在所取的10种组织中,雌性泰山赤鳞鱼在心脏、性腺、肾、眼、鳃和脾6种组织中存在苹果酸酶,而雄性泰山赤鳞鱼只在心、肌肉、性腺、眼和鳃5种组织中存在苹果酸酶。雌性鱼心脏组织中只有1条ME-2带,而雄性鱼心脏组织含有ME-1和ME-22条酶带;卵巢中含有ME-1和ME-22条酶带,而精巢中只含有ME-11条带;雌性鱼的眼组织含有ME-1带,而雄性鱼眼中含有ME-2带。肾和脾组织只在雌性鱼中含有苹果酸酶酶带,而肌肉组织只在雄性鱼中含有苹果酸酶。苹果酸酶的表型在泰山赤鳞鱼不同性别同一组织和同一性别不同组织之间都存在明显差异,但在同一性别的不同个体之间不存在差异。该研究结果为赤鳞鱼种群的发育遗传学、品种改良和定向育种提供了基础资料,为赤鳞鱼的开发和保护奠定基础。     

马桑根瘤内生菌纯培养物的分离、回接及其生物学特性

多次采用根瘤切片法直接从野生的马桑根瘤中分离内生菌纯培养物均未获成功;但用同样方法从温室里人工接种形成的马桑根瘤中却分离到大量纯培养物。其中273株经盆栽回接后发现有24株能侵染结瘤;少数菌株还通过半固体斜面和珍珠岩盆栽回接成功。对10株纯培养物表型特性的研究表明,它们均具有Frankia的形态和培养特征;生理类型除有A、B两型外,尚出现有一类A、B混合型,其中凡属B型菌株的均能侵染结瘤,A型则不能,两株A、B混合型中有1株能结瘤,另1株却不能;碳、氮源利用特性和其它Frankia基本相似;细胞壁组分既有Ⅲ型也有Ⅱ型;全细胞鉴别性糖大多为木糖和半乳糖,少数菌株只含有半乳糖或木糖,或含有半乳糖、木糖和阿拉伯糖。DNA中G+C mol%为65%～74%。