利用SSR标记鉴定结球甘蓝杂交种真实性及纯度

本研究利用公开发表的50对甘蓝SSR引物对5份结球甘蓝杂交种构建指纹图谱,对新调入的4个批次结球甘蓝杂交种与对照品种是否属于同一品种(即真实性)进行鉴定,并依据指纹图谱筛选双条带引物,对其中某一批次的10份杂交种进行纯度鉴定。指纹图谱鉴定结果表明:新调入4个批次杂交种中有3个批次与对照属于同一品种,1个批次与对照属于不同品种,与田间形态鉴定结果完全吻合。利用筛选出的SSR标记对10份甘蓝杂交种进行纯度鉴定,其中8份鉴定结果与田间形态鉴定结果一致,两种鉴定方法显著相关。本研究为利用SSR标记进行甘蓝杂交种真实性及纯度鉴定的实践可行性提供理论依据和参考。     

玉米和高粱SSR标记在薏苡中的通用性研究

旨在分析玉米和高粱SSR标记在其近缘种薏苡中的通用性和多态性，以期筛选可用于薏苡种质资源和遗传学研究的分子标记。以11份薏苡资源为供试材料，利用SSR-PCR扩增和毛细管电泳检测方法，对364对SSR引物进行了测试和筛选。结果表明，364对玉米和高粱来源的标记中有163对能在薏苡中扩增并得到清晰的条带，其中44对标记在薏苡中表现出良好的多态性。高粱SSR的通用性和多态性比例分别为58.02%和30.85%，玉米SSR标记的通用性和多态性比例分别为23.45%和26.47%，高粱SSR标记在薏苡中通用性和多态性更好。44对引物在11份薏苡材料中扩增出110条多态性条带，每对引物扩增出的条带数在1～5条之间，平均为2.5条，PIC为0.15～0.79，其中15对引物的PIC值大于0.5，占全部多态性引物的34.09%。筛选出的通用SSR引物可为薏苡种质资源多样性和分子遗传学研究提供可用的遗传标记，也是高粱、玉米和薏苡3种作物之间比较基因组学研究的有力工具。     

不同薏苡品种（系）生产力水平分析

为探究适合云南省薏苡种植的新品种（系）,以提高云南薏苡种植的生产力水平。通过对10个薏苡品系在云南省文山地区进行生产力的比较试验,对薏苡农艺性状（生育期、株高、茎粗、有效分蘖数、单株总果数、百粒重等）进行比较鉴定与评价,并对其产量进行分析比较。结果表明：1）有效分蘖数、单株总果数、百粒重与产量呈正相关,其中百粒重与产量的相关性显著;2）YLO、Y7—1生育期较短,植株较矮,茎秆细,株型紧凑,抗倒伏性强,是理想的株型;3）Y9—7、Y3—4、Y12—2黑为中晚熟品种,百粒重高、籽粒外观好、产量高;4）YGL、文薏二号为晚熟品种,生育期在150~155天之间,植株高、分蘖力强、茎秆粗、生物产量高,但经济产量较低;5）从薏苡的综合性状、产量、适应性等指标来看,参试的品系Y9—7、Y3—4、Y12—2（黑）优势明显,更符合选育优质、高产的新品种（系）。     

SSR荧光标记在80份荷花品种指纹图谱构建中的应用

本研究利用毛细管电泳技术对筛选出的8对SSR荧光引物进行检测,构建了80个荷花品种的指纹图谱。8对引物共检测到52个多态位点,多态位点数平均为6.5;多态性信息含量PIC值变化范围为0.41~0.81,平均为0.62。利用其中5对引物SSR022、SSR035、SSR468、SSR87和CL06可区分供试的80个荷花品种。利用获得的SSR指纹图谱数据,对80份荷花品种进行聚类分析,结果表明,在遗传相似系数0.435处供试荷花材料可分为7大类群。本研究利用SSR荧光标记技术,获得了供试荷花材料的指纹图谱,进一步分析了品种间亲缘关系的远近,可为荷花种质资源的分类及鉴别提供依据。     

薏苡种质资源的AFLP遗传多样性分析

薏苡是传统药食兼用经济作物,本研究基于AFLP分子标记技术对来自贵州、云南、广西3省24份优良材料的遗传多样性和亲缘关系进行分析,以期为薏苡杂交组合选配和种质创制提供遗传基础。结果表明:我们筛选出的8对引物组合共扩增条带996个,其中多态性为792条,多态性百分率的平均为79.52%,揭示薏苡种质中存在丰富遗传多样性;24份种质的遗传距离范围在0.189 6～0.485 4之间,相似系数变异范围为0.615 5～0.840 4,平均相似系数为0.730 9,薏苡种质资源的遗传相似系数较小;根据遗传相似性系数进行聚类分析,当遗传相似系数为0.718 5时,24份薏苡种质资源在遗传聚类上被分为Ⅰ、Ⅱ、Ⅲ和Ⅳ大类,其中CK与S1种质资源分别为第Ⅰ、Ⅳ类群,由Y81、Y81F组成第Ⅲ类群,第Ⅱ类又可以分为3个亚类有20份种质;主成分分析发现材料间分布分散,说明24份薏苡种质资源之间存在较大遗传变异,分子主效应分析结果与分子聚类结果一致。从而说明AFLP是研究薏苡种质资源遗传多态性及亲缘关系的有效手段之一,为薏苡亲本组合选配、种质创制和遗传育种提供遗传基础数据。     

亚麻抗派斯莫病种质资源筛选

为了解不同亚麻种质对派斯莫病的抗性差异,采用菌土接种法进行盆栽试验,统计分析各种质的发病情况并计算病情指数,对20个亚麻品种(系)进行派斯莫病抗性鉴定与评价。根据病情指数将20个亚麻品种(系)的派斯莫抗性分为抗病、中感、感病和高感。试验结果表明：不同品种（系）间存在明显的抗性差异,但整体抗性较差,无免疫品种（系）;有7个抗病品系,分别为H2012-1、ZY03001-2-4、Y0310-7-3、ZY03119-2-12、ZY06175-10-15、01059-1-6-2、9804-38,占供试种质总数的35%;中感、感病和高感品种(系)分别为9、2、2份,共占供试种质总数的65%,因此,H2012-1、ZY03001-2-4等7个抗性较强的品系可作为亚麻抗派斯莫病育种的材料。     

小麦SSR指纹图谱及品种身份证的构建——基于毛细管电泳分析

为解决小麦品种区分难的问题,以黄淮海和长江中下游地区160个小麦主栽品种为试验材料,经初筛和复筛,从分布于小麦21个连锁群的105对SSR引物中,筛选出21对稳定、多态性高的引物(每条染色体上各选取1对)。对供试小麦品种进行SSR荧光标记的毛细管电泳分析,获取其SSR分子指纹信息,并与品种基本商品信息结合,进行数字化编码,构建了160个小麦的品种身份证,实现小麦品种信息唯一性、通用性、可识别性和可追溯性的统一,为小麦种子的质量追溯和管理提供便利,同时为种子市场的知识产权保护提供科学依据。     

燕麦光照不敏感基因SSR分子标记的引物筛选

光周期是影响植物生长发育的关键因素之一。燕麦(Avena sativa L.)是长日照作物,必须要经过长日照条件才能正常开花结实,这使燕麦的播种时间以及地理分布都受到了限制。以光照敏感品种白燕1号与光照不敏感品种VOA-8杂交,F_1自交得到210个F_2代群体。以白燕1号、VOA-8及F_2群体为材料,对306对SSR引物进行了筛选。结果表明,在306对SSR引物中,25对在亲本间表现出多态性,多态率为8.17%。利用筛选出来的25对SSR引物对2个亲本和F_2个体进行进一步检验,9对引物在群体间存在多态性,可用于群体筛选。以上研究为进一步构建燕麦SSR遗传连锁图谱和进行燕麦F_2代群体光照不敏感基因QTL定位提供了帮助。     

2012年北方春大豆国家区试大豆品种纯度鉴定、分子ID构建及遗传多样性分析

为了鉴定北方春大豆组国家区域试验大豆品种的纯度、构建参试大豆品种的分子ID及品种间遗传关系分析,从而有效地指导中国北方春大豆新品种的选育和推广。通过对参加2012年北方春大豆国家区试的94份大豆材料用分布在大豆基因组8个连锁群的13对SSR标记进行分析。结果表明：94份参试大豆品种纯度分布范围为53.85%~100%,平均纯度为99.02%;利用Satt231、Satt288、Satt160、Satt193和Sat-092这5对引物可以将94份参试大豆品种区分开,并获得唯一的分子ID;94个参试大豆品种间遗传相似系数为0~0.846,平均相似系数为0.2783,说明参试大豆品种间遗传差异性较大。通过SSR标记分析,可以有效地鉴定参试大豆品种的纯度、建立参试大豆品种的分子ID及实现品种间遗传关系分析。     

川东北丘陵区不同基因型水稻品种对比试验初报

为筛选出适宜在川东北丘陵区种植的高产水稻品种,开展了11个不同基因型水稻品种比较试验。试验结果表明:Q优28、宜香10号、川谷优918、内5优317、健优388、冈优558、川香优37的产量均高于对照冈优725,比较适宜在川东北丘陵区种植。在所有供试材料中,尤其以内5优317和川香优37表现最优,其产量显著高于对照。     

A note on the origin of Kalanchoë x vadensis Boom & Zeilinga (Crassulaceae)

Summary K x vadensis is a hybrid of K. blossfeldiana and K. marmorata obtained after doubling the number of chromosomes.     

Avoidance of leaf rust fungi in wild relatives of cultivated cereals

Summary Avoidance of rust fungi that was based on poor appressorium induction was previously found in Hordeum chilense. In the present study 95 accessions of Triticeae were screened for avoidance of Puccinia hordei. The percentage of appressorium formation per germinated spore ranged from 6 to 90%. On none of the 41 accessions of Aegilops, Agropyron, Elymus, Secale, Thinopyrum or Triticum studied was the rate of appressorium formation lower than 25%. Lower rates of appressorium formation were, however, found on accessions of wild barley species Hordeum brachyantherum, H. marinum, H. parodii and H. secalinum. Its implications in cereal breeding are discussed.     

Relation between wheat-rye crossability and seed set of common wheat after pollination with other species in the Hordeae

Summary Cultivars of common wheat (Triticum aestivum L. em. Thell.) of high wheat-rye (Secale cereale L.) crossability set more seed with pollen of other related species than did wheats of low wheat-rye crossability. This was found to be true for pollen parents from the genera Triticum, Aegilops, Secale, Agropyron and Elymus.     

Mechanisms and diversity of resistance to sorghum shoot fly,Atherigona soccata

Sorghum shoot fly, Atherigona soccata, is one of the important pests of postrainy season sorghums. Of the 90 sorghum genotypes evaluated for resistance to this pest, RHRB 12, ICSV 713, 25026, 93046 and 25027, IS 33844‐5, Giddi Maldandi and RVRT 3 exhibited resistance in postrainy season, while ICSB 463, Phule Anuradha, RHRB 19, Parbhani Moti, ICSV 705, PS 35805, IS 5480, 5622, 17726, 18368 and 34722, RVRT 1, ICSR 93031 and Dagidi Solapur showed resistance in rainy season, suggesting season‐specific expression of resistance to A. soccata. ICSB 461, ICSB 463, Phule Yasodha, M 35‐1, ICSV 700, 711, 25010, 25019 and 93089, IS 18662, Phule Vasudha, IS 18551 and 33844‐5 and Barsizoot had fewer deadhearts than plants with eggs across seasons, suggesting antibiosis as one of the resistance mechanism. Five genotypes exhibited resistance with high grain yield across seasons. Correlation, path and stepwise regression analyses indicated that leaf glossiness, seedling vigour, trichome density, oviposition and leaf sheath pigmentation were associated with the expression of resistance/susceptibility to shoot fly, and these can be used as marker traits to select and develop shoot fly‐resistant sorghums.     

Reaction of tritordeum to Fusarium culmorum and Septoria nodorum

Summary Hordeum chilense is a wild barley extensively used in wide crosses in the Triticeae. It could be a valuable source of resistance to Fusarium culmorum and Septoria nodorum. Some H. chilense x Triticum spp. amphiploids, named tritordeums, were more resistant than the parental wheat line to these diseases, others were not. Average contents of ergosterol and deoxynivalenol (DON) suggested that resistance to colonization by Fusarium was the highest for Hordeum chilense, followed by tritordeum and wheat in decreasing order. In particular, the H. chilense genotypes H7 and H17 enhanced the wheat resistance to F. culmorum in its tritordeum offsprings. Resistance to S. nodorum in tritordeum was not associated with tall plant height. There is sufficient genetic variation for resistance to F. culmorum and S. nodorum among tritordeum to allow the breeding of lines combining short straw and resistance to both diseases.     

Disease resistance in protected crops and mushrooms

Summary Cultivars of tomatoes, cucumbers, lettuce and peppers have been bred for resistance to one or more pathogens. Some tomato and cucumber cultivars have resistance to a wide range of diseases. Resistance has been transient in many cases and a succession of cultivars with new genes or new combinations of resistance genes has been necessary to maintain control. There has been a number of notable exceptions and these have included durable resistance to such pathogens asFulvia fulva and tomato mosaic virus. With lettuce the resistance situation is complicated by the occurrence of fungicide resistant pathotypes. There are no strains ofAgaricus bisporus purposely bred for disease resistance.In protected flower crops only resistance to Fusarium wilt in carnations has been purposely bred but differences in disease resistance are apparent in cultivars of many ornamental crops. This is particularly so in chrysanthemums where there are cultivars with resistance to many of the major pathogens. Similar situations occur with other flower crops and pot plants. Cultivars of some species have not been systematically investigated for resistance.The need for genetic resistance will increase with the further reduction, in the limits on pesticide use and an increasing public awareness and importance of pesticide pollution.ADAS is an executive agency of the Ministry of Agiculture, Fisheries and Food and the Welsh Office.     

Breeding apomictic bahiagrass (Paspalum notatum Flügge) with improved turf traits

The development of a turf‐type bahiagrass could have a remarkable impact on the billion‐dollar turf industry in the south‐eastern United States. The goals of this study were to (i) select bahiagrass genotypes with improved turf attributes and (ii) determine the reproductive mode and seed fertility of selected genotypes. The population included mutants, wild types, hybrids and standard cultivars evaluated at two locations for two years. Morphological variation was observed and clonal repeatability (H²) ranged from 0.27 to 0.90. Flowering was extremely reduced in some mutants, which also exhibited dark green colour, finer texture and reduced canopy height. Cytoembryological observations revealed that diploids reproduced sexually and tetraploids by obligate or facultative apomixis. Genotypes with superior seed fertility were identified, while others were comparable to the standard cultivars. While mutant plants exhibited great morphological variation, the random mutations did not affect their reproductive mode, validating the use of mutagenesis in apomictic species. The high H² indicated that selection for improved turf attributes could be successfully performed with the advantage of clonal seed propagation.     

Genetic constitution and diversity in four narrow endemic redwoods from the family Cupressaceae

The genetic constitution and diversity of four relictual redwoods are discussed in this review. These include monotypic genera of the family Cupressaceae: coast redwood (Sequoia sempervirens), giant sequoia (Sequoiadendron giganteum), dawn redwood (Metasequoia glyptostroboides), and alerce (Fitzroya cupressoides). All four species are narrow endemics, share a number of common phenotypic traits, including red wood, and are threatened species. Fossil history suggests that the ancestors of redwoods probably originated during the Cretaceous and Tertiary periods and flourished thereafter for millions of years. Towards the end of the Tertiary period began their decline and struggle for existence that continued during the subsequent geologic upheavals and climate changes, until the survival of the present-day redwoods in the current restricted locations in the world (USA, China, and South America). Although two species, Sequoiadendron and Metasequoia, are diploids (2n = 22), and the other two are polyploids: Fitzroya a tetraploid (2n = 4x = 44), and Sequoia a hexaploid (2n = 6x = 66); they all share the same basic chromosome number x = 11. The genome size in the hexaploid Sequoia is one of the largest (31,500 MB) in the conifers, while the genome sizes of diploid Metasequoia and Sequoiadendron are about one-third (~10,000 MB) of Sequoia. Genetic diversity in the redwoods is lower than most other gymnosperms, except in Sequoia, which seems to rank near the upper quarter of the coniferous forest trees. Genomic research is sparse in the redwoods, and should be pursued for a better understanding of their genome structure, function, and adaptive genetic diversity.     

Inheritance of fruit colour in a wild Russian red raspberry seedling

Summary A new gene, i, from a self-incompatible wild Russian Rubus idaeus seedling is described. The gene i interacts with the fruit colour gene T, Tii plants having apricot instead of red fruits, and spines, leaves and stems pigmented to varying degrees. A deficit of apricot-fruited seedlings in progenies segregating for i could be explained by linkage between i and the self-incompatibility S locus with a crossover value of approximately 26.7%.Segregations for spine colour in crosses and backcrosses of the Russian seedling with two green-spined (ttII) raspberries selected for their yellow fruit colour, showed that both the latter carried the spine colour intensifier gene P. This suggests that earlier authors were incorrect in attributing the apricot fruit colour developed by some tt plants to a pleiotropic effect of P.     

The induction in vitro of adventitious shoots in Rosa

Summary Adventitious shoots were formed on excised leaves, roots and callus of Rosa persica x xanthina and on excised leaves of R. laevigata and R. wichuraiana on culture media that included BAP and NAA as growth regulators. Shoots formed freely on freshly cultured callus of R. persica x xanthina but their production declined in successive cultures and ceased after twelve weeks. Transplantation to soil was improved by rooting plantlets in cellulose plugs in vitro and transferring plantlets to soil while still in the plugs.