小麦品种百农AK58及其姊妹系的遗传构成分析

百农AK58是目前我国黄淮南部麦区大面积种植的小麦品种。利用表型、高分子量麦谷蛋白亚基、蛋白质含量及覆盖小麦全基因组的657对SSR分子标记分析了百农AK58姊妹系及其亲本的遗传构成, 以发现大面积品种的亲本选配规律。百农AK58在小穗数、穗粒数、千粒重和单株穗数上略优于其姊妹系丰收60和百农4330。百农AK58的高分子量谷蛋白亚基组合与亲本郑州8960相同, 为(1, 7+8, 5+10), 其姊妹系丰收60和百农4330的亚基组合与亲本温麦6号相同, 均为(1, 7+9, 5+10)。SSR标记分析表明, 百农AK58对亲本周麦11、温麦6号和郑州8960遗传成分的继承率分别为47.4%、28.9%和23.7%, 而丰收60的继承率分别为47.9%、30.7%和21.4%。可见, 这2个品种在遗传上与周麦11有较大的相似性。百农4330继承这3个亲本的遗传成分比例非常相近, 分别为33.1%、32.4%和34.6%。在A、B、D基因组及染色体水平上, 3个亲本品种对后代的遗传贡献率也表现不均衡性。百农AK58有40个不同于丰收60和百农4330的SSR特异位点, 主要分布于1A、4A、5A、6A、1B、4B、5B、6B、7B、1D、2D、3D和7D染色体, 其中多数位点已知存在与产量、抗病等重要农艺性状相关的基因, 推测这些特异位点在百农AK58成为大面积种植品种中发挥了重要作用。     

应用SSR分子标记分析小麦品种(系)的遗传重组

为了解小麦品种形成中亲本基因组的遗传重组和遗传保留区段的分布特点,对周麦18和百农AK58及其衍生品系共23个材料进行了全基因组SSR扫描分析。遗传重组分析表明,单交组合的平均重组数(12.3)低于回交组合(13.9);染色体4A、5A、7A、1B、3B、4B、7B、1D、2D、3D、5D、6D和7D重组发生较多,其余染色体重组相对较少,染色体的中间区段与远端区段重组数相当,分别为6.1和6.0。子代间基因组比较发现,一些染色体区段成为重组的多发区,如5D的gwm358–wmc357、6D的cfd49–barc196、7A的wmc158–barc23和7B的gwm274–gwm146区段,分别有35、19、15和14次重组。分析亲本传递给子代的染色体区段,发现子代继承亲本的遗传区段在14~29个,每个区段涉及2~8个多态性位点,大的遗传区段主要分布于4A、5A、5B、5D和7D染色体。以上基因组区域的关联性状是进一步研究的重点。     

利用SSR分子标记分析彩色小麦的亲缘关系与遗传多样性

为探讨彩色小麦的亲缘关系和遗传多样性, 利用305对多态性SSR引物检测了18个彩色小麦品种(系)。共检测到1 084个等位变异, 平均每对引物检测到3.6个。红粒、紫红粒小麦的等位变异数在7个部分同源群的排序为HG3>HG2>HG1>HG4>HG5>HG7>HG6, 黑粒和蓝粒小麦的排序为HG3>HG2>HG1和HG4>HG5>HG7>HG6。不同粒色小麦的SSR标记多态信息含量相近, 其中红粒和紫红粒小麦为0.525~0.543, 黑粒和蓝粒小麦为0.517~0.545。18个品种(系)的遗传差异极显著(P=0.0001), 遗传相似系数在0.41~0.76之间。UPGMA聚类分析将18份材料分为6群,类群分布与亲缘关系及其地域相关。     

小麦分子标记在长穗偃麦草的通用性

利用小麦的600对SSR、391对EST-SSR、35对STS和149对PLUG引物分别对普通小麦品种YN001和十倍体长穗偃麦草基因组DNA进行扩增,旨在分析不同标记在长穗偃麦草的通用性。398(66.3%)对SSR、294(75.2%)对EST-SSR、33(94.3%)对STS和126(84.6%)对PLUG引物在长穗偃麦草有清晰的扩增条带,4种类型引物在长穗偃麦草和小麦间表现多态扩增的引物比例分别为61.0%、68.0%、82.9%和79.9%,表明这4种引物均可以用于长穗偃麦草的遗传研究,但STS和PLUG引物效果优于SSR和EST-SSR。进一步分析基因组SSR和EST-SSR引物的核心单元组成,发现二者在长穗偃麦草有效扩增的引物以二核苷酸和三核苷酸重复为主要类型。     

小麦RIL群体第一部分同源群染色体遗传多样性与偏分离分析

为了明确小麦第一同源群染色体的遗传多样性,用小麦重组近交系群体(RIL)(Q9086×陇鉴19)108个株系为材料,利用SSR标记对小麦第一同源群进行遗传多样性和偏分离分析。结果表明,97对SSR引物在RIL群体亲本间筛选具有多态性标记23对,多态性频率1B(30.30%)>1A(28.57%)>1D(10.34%)。在RIL群体中检出107个等位位点有多态性,每个引物可扩增出2～10个位点,平均4.65个。每个位点多态信息含量(PIC)在0.326～0.880之间,PIC值1B(0.709)>1A(0.534)>1D(0.498)。株系间遗传相似系数(GS)在0.40～0.96之间。通过聚类可将RIL群体分为九大类。亲本基因型在群体中的分离比例为1∶1.13。通过χ2检测,有15个SSR标记表现为偏分离(P<0.05),偏分离频率为65.2%,其中,有7个标记偏向父本陇鉴19,8个标记偏向母本Q9086;6个标记偏分离在1A上,7个偏分离在1B上,2个分布在2D上。     

小麦品种周麦16的遗传构成分析

为解析小麦骨干品种周麦16的分子遗传学基础,本研究利用覆盖小麦全基因组的90 K SNP标记对小麦周麦16及其亲本进行全基因组扫描。结果表明,2个亲本对周麦16的遗传贡献差异较大,周8425 B对周麦16的遗传贡献率为64.32%,远高于周麦9号对周麦16的遗传贡献率(35.68%);在不同基因组水平上,周8425 B对周麦16的遗传贡献均高于周麦9号的遗传贡献率;在不同染色体上,2个亲本对周麦16的遗传贡献各有侧重,周麦9号在2 A、2 D、6 A、6 B染色体上对周麦16的遗传贡献率均达到60%以上,而在1 B、3 D、5 A、5 D和6 D染色体上周8425 B对亲本的遗传贡献率达到80%以上。本研究明确了周麦16的分子遗传构成,为周麦16利用提供参考依据。     

小麦新、老种子活力与其酶关系的研究

以周麦18、百农AK 58两种小麦的新、老种子为试验材料,进行小麦发芽试验、老化处理和抗冻处理来了解两个品种新、老种子的活力情况;再通过测吸光值法对两品种新老种子的过氧化物酶(POD)、超氧化物歧化酶(SOD)、过氧化氢酶(CAT)的活性进行测定.结果表明,同一品种小麦的新种子在3种条件下的发芽率明显大于其老种子;同一品种小麦的新种子的过氧化物酶、超氧化物歧化酶、过氧化氢酶的活性明显大于其老种子,电泳图谱结果也与之一致.种子活力与种子内过氧化物酶、超氧化物歧化酶、过氧化氢酶的活性成正相关.另外,从周麦18,百农K 58的相关数据和酶谱的对比,得知百农AK 58的种子活性及其稳定性明显优于周18.     

中秆高产冬小麦品种小区试验边行产量和内行产量研究

以4个半冬性中秆小麦品种周麦18、百农207、华育198和郑育8号为材料,对小区试验各行的内行折单产、边行折单产、全小区折单产和产量构成因素进行了研究。结果表明:1)各品种均有明显的边行优势,并且不同品种间有着较明显的差异。其中以郑育8号边行优势最强,为57.85%;百农207次之,为55.29%;周麦18居第3位,为29.69%;以华育198的边行优势最弱,为20.74%。2)4个品种的穗数、穗粒数和千粒重均表现一定的边行优势,以穗数边行优势最大、穗粒数边行优势居中、千粒重边行优势最小,依次平均边行优势为18.58%、14.21%和2.94%。不同品种穗数的边行优势由大到小依次为郑育8号百农207周麦18华育198;穗粒数的边行优势从多到少依次为百农207周麦18郑育8号华育198;千粒重的边行优势从高到低依次为百农207郑育8号周麦18华育198。3)以边行折单产,各品种产量高低依次为百农207郑育8号华育198周麦18;以内行折单产,各品种产量高低依次为华育198百农207郑育8号周麦18。以全小区折单产,各品种产量高低依次为百农207郑育8号华育198周麦18。     

小麦微卫星标记在中间偃麦草中通用性研究

利用分布于普通小麦整个基因组的525对微卫星引物,对其在普通小麦与中间偃麦草(Thinopyrumintermedi-um)之间的通用性及其亲缘关系进行了分析。结果表明:202对引物在小麦和中间偃麦草间多态性扩增,所占比率为38.4%,小麦的A,B,D3个基因组多态性引物所占比率分别为34.6%,36.9%和42.2%;说明普通小麦SSR引物在中间偃麦草之间具有通用性,小麦D基因组与中间偃麦草亲缘关系要远于A,B基因组与中间偃麦草关系,表明小麦的A,B,D基因组之间存在遗传差异性。     

青海省审定小麦品种SSR遗传多样性分析及分子身份证的建立

小麦是青海省重要的粮食作物,本研究从分子水平上明确青海省审定小麦品种的遗传多样性现状并建立其分子身份证,为青海省小麦育种和资源保护提供理论依据。利用从520对SSR引物中筛选出的212对具有清晰扩增条带的引物,对青海省66个育成小麦品种进行研究。结果表明,19对引物扩增结果表现为单态,193对引物扩增结果表现为多态,共扩增出724个等位变异,变异范围为2~10个。多态性引物的多态信息含量（polymorphism information content,PIC）变化范围为0.03~0.86,平均为0.51。A、B、D 3个基因组的平均等位变异丰富度（allelic richness,R_s）和平均遗传多样性指数（Nei’s genetic diversity index,H_e）均为A>B>D。小麦的7个同源群中,第2同源群多样性指数最高,第7同源群多样性指数最低。在多样性研究的基础上,利用23对引物组合,构建了66个小麦品种的分子身份证,可将它们完全区分开,为青海省小麦品种的鉴定提供参考。     

Location of a high-lysine gene and the DDT-resistance gene on barley chromosome 7

Summary The high-lysine gene in Risø mutant 1508 conditions an increased lysine content in the endosperm via a changed protein composition, a decreased seed size, and several other characters of the seed. The designation lys3a, lys3b, and lys3c, is proposed for the allelic high-lysine genes in three Risø mutants, nos 1508, 18, and 19. Linkage studies with translocations locate the lys3 locus in the centromere region of chromosome 7. A linkage study involving the loci lys3 and ddt (resistance to DDT) together with the marker loci fs (fragile stem), s (short rachilla hairs), and r (smooth awn) show that the order of the five loci on chromosome 7 from the long to the short chromosome arm is r, s, fs, lys3, ddt. The distance from locus r to locus ddt is about 100 centimorgans.     

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.     

Simultaneous Determination of Four Phenolic Acids in Radix Salviae Miltiorrhizae Formula Granules by QAMS

[Objectives]This study aimed to establish a QAMS(quantitative analysis of multi-components by single-marker)method for simultaneous determination of four phenol...     

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.     

Pollen and pollination experiments. III. The viability of apple and pear pollen as affected by irradiation and storage

Summary Apple and pear pollen was irradiated with doses of 0, 50, 100, 250 and 500 krad (gamma rays) and stored at 4°C and 0–10% r.h. From the in-vitro germination percentages an average LD 50 dose of about 220 krad was estimated. For both irradiated and untreated pollen a close and corresponding lineair relationship existed between germination percentage and pollen tube growth.Irradiated pollen was much more sensitive to dry storage conditions than untreated pollen, resulting in less germination and more bursting. Apparently, irradiation caused the pollen cell membrane to lose its flexibility faster than normal. Rehydration of dry-stored, irradiated pollen in water-saturated air restored germination percentages up to their initial levels. The importance of this procedure in germination trials is stressed.     

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.     

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.     

Evolution under domestication involving disturbance of genic balance

Summary An hypothesis is developed that the rapid change from wild plants into domesticated crops principally involves the selection of alleles with non-functional gene products which leads to reduced control of the highly integrated metabolism and morphogenesis previously accumulated by lengthy natural selection. Such disturbance of the genome produces altered physiological and morphological development which, although deleterious in nature, serves mankind better and has been selected.