冬小麦杂种F1及其亲本光合特性的研究初报

研究了10个冬小麦(Triticum aestivumL.)杂交组合的子一代(F1)及其亲本的光合特性.结果表明,在这10个杂交组合中,虽然只各有4个杂交组合的F1的PSⅡ总的光化学量子产额(Yield)和光化学荧光猝灭系数(qP)有超亲现象,但绝大多数组合的F1光合功能都与母本十分相近,正反交组合的结果进一步证明这种相关性.可见,母系遗传对于F1光合功     

中美几个棉花品种育种应用价值研究

用3个美国陆地棉品种为母本与2个中国品种配制6个杂交组合。5个亲本与其6个杂交组合F2和F3种植在美国密西西比州立大学农业试验站。利用加性 显性 加×加互作遗传模型(ADAA)进行数据分析。结果表明,除了加性和显性效应外,加×加互作效应控制大多数农艺性状和纤维性状。两个中国品种均可用于纤维麦克隆值的改良。品种CR110及Deltapine90(DP90)在纤维长度和强度方面具有较好的一般配合力。与品种DP90的杂交组合可以在较晚世代用于产量的改良。杂交组合Stoneville474(ST474)×CR110可用于在早期提高皮棉产量。除ST474×CR110之外,其它各组合均具有产量改良的潜力。组合Sure Grow747(SG747)×86 1在早期和晚期均比其它组合有较高的纤维强度。考虑到皮棉和纤维品质的基因型值,组合SG747×86 1可用于提高早期和晚期产量的改良且有好的纤维品质。     

棉花杂种优势与亲本表现的关系研究

以3个高品质棉品系做母本,分别以大铃、高品质、高衣分种质做父本,配制了9个杂交组合.通过分析9个陆地棉品种间杂交组合的杂种优势表现,研究了杂种F1产量优势与亲本表现的关系.结果表明,杂种F1的产量优势由父母本共同决定,在母本相同的情况下,F1产量优势决定于父本,而在父本相同的情况下,F1产量优势决定于母本;在母本相同的情况下,F1铃数、铃重、衣分、株高的平均竞争优势决定于父本.     

农艺性状优良冬小麦ph1b系的创造及标记辅助选择的应用

利用改进的桥梁亲本法, 即以阿勃5B缺体为桥梁亲本, 分别与受体冬小麦推广品种(农大95、 京411和京冬8号)和中国春ph1b突变体杂交, 两个组合F1(即5BPh1和5Bph1b单体)再杂交, 后代选择5Bph1b单体与受体亲本5BPh1单体杂交, 仅3个世代就获得了3个冬小麦ph1b中间育种系, 在杂交转育过程中, 我们用先前获得的3个SCAR标记对5     

优质高产杂种冬小麦品种选育途径探讨

对冬小麦15个F1杂交组合杂种优势与其沉降值变化趋势分析结果表明,F1中有强优势组合,其超标幅度5.1%～56.6%,亲本材料基因重组后,沉降值变化为超亲组合占33.3%,趋近父母亲本平均值的组合占60%.综合分析结果表明选用优质亲本,组配强优势组合和采用化学杀雄技术,可以选育优质高产杂种冬小麦品种.应用微量SDS沉降值指导田间早代选择非常有效.     

15个冬小麦杂种一代产量与品质研究

对冬小麦 1 5个F1 代杂交组合的杂种优势与其沉降值变化趋势分析结果表明 :F1 代中有强优势组合 ,其超标幅度 5.1 %～56.6%。亲本材料基因重组后 ,沉降值变化为 :超亲组合占 3 3 .3 % ,趋近父母亲本平均值的组合占 60 %。综合分析结果表明 :选用优质亲本 ,组配强优势组合和采用化学杀雄技术 ,可以选育优质高产杂种冬小麦品种。应用微量SDS沉降值指导田间早代选择非常有效     

普通小麦品种间以及与六倍体小黑麦种间杂种F1农艺性状的遗传分析

为给杂交选育优良小麦品种提供基础,本研究以普通小麦品种晋农190为父本,分别与9个普通小麦品种、7个六倍体小黑麦品种为母本配置杂交组合,对杂种F1代的农艺性状进行分析,发现除了无芒对有芒为显性之外,其余农艺性状均表现为数量遗传,F1代表现为超亲遗传或介于双亲之间。六倍体小黑麦的灰绿色叶片或茎秆、穗长长和红色不饱满的籽粒在杂种F1代显现,可作为鉴别真假杂种的典型性状。     

水稻分蘖期强势和弱势F_1基因表达差异分析

本研究利用DD-PCR技术,对杂交水稻强势和弱势F1在分蘖期基因表达模式的差异进行了分析。根据F1不同带型的比例进行聚类分析,结果显示6个F1被分为强势和弱势两个类群。它们在多个基因表达类型上存在差异,其中强势组合的DMP1(F1与母本共表达)与DMP2(F1与父本共表达)均明显高于弱势组合,而UNP2(父本特异表达)、ABF1(F1特异缺失表达)和MONO(双亲与F1共表达)则明显低于弱势组合。同时,对6个强势组合中表达而弱势组合沉默的特异条带进行了克隆测序,功能分析表明,T2、T3、T5分别与蛋白激酶(AK101690)、丝氨酸/苏氨酸蛋白磷酸酯酶PP2A-4催化亚基(AK099604)和细胞色素P450家族蛋白(AK067549)的功能类似,它们在植物抗逆性方面具有重要调节作用。     

春小麦新品种青麦2号的选育

<正>青麦2号(原代号04-53)是青海省大通县农业技术推广中心2004年以冬小麦济宁13为母本、春小麦97256选系为父本,通过有性杂交多年系谱选育而成的抗病、优质、高产、抗倒伏的春小麦新品种。2013年12月经青海省第八届农作物品种审定委员会第三次会议审定通过,审定编号:青审麦2013001。1选育经过2004年用济宁13为母本、春小麦97256选系为父本进行田间杂交,同年秋季收获杂交F0种子。2005年将F0种子进行点播,共选F1单株28株。     

两系亚种间杂交稻籽粒充实度的遗传研究

本研究选用了10个籼型光温敏不育系作母本,10个粳型广亲和品种作父本,共配制籼粳亚种间杂交组合53个.从两系亚种间杂交稻籽粒充实度的遗传方面进行研究,结果表明:(1)两系亚种间杂种F1的谷粒充实率与其本身的程氏指数相关不显著,相关系数仅为-0.1818;与双亲的亲缘距离(程氏指数差值)极显著负相关,相关系数为-0.4739**.(2)两系     

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.     

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.     

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.     

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.     

Distribution,ecology and reproductive biology of wild tomatoes and related nightshades from the Atacama Desert region of northern Chile

Over the past 20 years, several expeditions were made to northern Chile to collect populations of wild tomatoes (Solanum chilense, S. peruvianum) and allied nightshades (S. lycopersicoides, S. sitiens), and obtain information about their geographic distribution, ecology and reproductive biology. Restricted mainly to drainages of the Andean and the coastal cordillera, populations are geographically fragmented. The two nightshade species are rare and threatened by human activities. Adaptation to extreme aridity and soil salinity are evident in S. chilense and S. sitiens (the latter exhibits several xerophytic traits not seen in the tomatoes) and to low temperatures in S. lycopersicoides and S. chilense. All tested accessions are self-incompatible, with the exception of one S. peruvianum population collected at the southern limit of its distribution. Several distinguishing reproductive traits—anther color, attachment, and dehiscence, pollen size, and flower scent—suggest S. sitiens and S. lycopersicoides attract different pollinators than S. chilense and S. peruvianum. The four Solanum spp. native or endemic to Chile provide a variety of novel traits which, through hybridization and introgression with cultivated tomato, could facilitate development of improved varieties, as well as research on a variety of basic topics, including plant-pollinator interactions, abiotic stress responses, and evolution of reproductive barriers.     

The exploration of genetic resources of Portuguese cabbage and kale for resistance to several Brassica diseases

Summary Twenty three accessions of nine Portuguese cabbage and kale land races from different geographic origins were tested at the seedling stage for resistance to several important brassica diseases. Resistance to downy mildew (Peronospora parasitica), expressed as necrosis of the cotyledon mesophyll, was found in all the accessions. Type A resistance to cabbage yellows (Fusarium oxysporum f. sp. conglutinans race 1) was present in most of the landraces. Resistance to clubroot (Plasmodiophora brassicae race 6) was found in one accession of the Portuguese tree kale. High resistance to blackleg (Leptosphaeria maculans) and white rust (Albuco candida) was not detected, although several accessions showed 20 to 30% of plants with intermediate expression of resistance. All Portuguese cole accessions were susceptible to blackrot (Xanthomonas campestris pv. campestris).     

Production and characterization of intergeneric diploid cybrids derived from symmetric fusion between Microcitrus papuana Swingle and sour orange (Citrus aurantium)

Plants were regenerated from intergeneric somatic hybridization between embryogenic protoplasts of Microcitrus papuana Swingle and leaf-derived protoplasts of sour orange (Citrus aurantium L.) via electrofusion. The regenerated plants were morphologically similar to the leaf parent in growth vigor, leaf and branch structure. FCM analysis showed that they were diploids. Simple-sequence-repeat (SSR) and cleaved-amplified-polymorphic-sequence(CAPS) were employed for hybridity characterization. SSR banding patterns of the regenerated plants were identical to the leaf parent, sour orange, indicating that they possessed nuclear component derived from sour orange. DNA amplification with chloroplast and mitochondrial universal primers, followed by restriction endonuclease digestion, revealed polymorphism between the fusion parents. Therefore, this method was used to determine the cytoplasmic compositions of the regenerated plants. Banding patterns for all the polymorphic primer/enzyme combinations of the regenerated plants were similar to those of the embryogenic parent, M. papuana, suggesting that only the cytoplasmic components derived from the embryogenic parent were present in the regenerated plants. FCM, SSR and CAPS demonstrated that intergeneric diploid cybrids have been successfully obtained by symmetric fusion. Related results concerning nuclear and cytoplasmic composition of previous diploid somatic hybrids and potential mechanism for regeneration of such kind of plants are discussed herein. This revised version was published online in July 2006 with corrections to the Cover Date.     

Breeding barriers between the cultivated strawberry, Fragaria × ananassa, and related wild germplasm

Five-hundred interspecific and intergeneric crosses were performed among accessions of the wild strawberries Fragaria vesca(2x), Duchesnea indica (8x), Potentilla tucumanensis (2x) and 9 genotypes of the cultivated strawberry, Fragaria×ananassa (8x), following an incomplete diallele mating design. Crosses between D. indica and F.×ananassa produced many putative hybrids when D. indica was used as female but a few achenes and plants when used as male; therefore, pollen-pistil compatibility relations were analyzed by fluorescence microscopy in this direction of the cross. Of the genotypic combinations, 78.6% were incompatible at the stigma level and 17.2% at the first third of the style. Only 3.6% were pollen-pistil compatible and produced fruits with achenes (seven did not germinate or originated short-lived plants and nine produced normal plants). F.vesca×F.×ananassa crosses produced 35 hybrid achenes but only 14% germinated, yielding short-lived plants; histological analyses revealed that inviable seeds had less developed (or collapsed) endosperms and smaller embryos than control plump F. vesca seeds. P.tucumanensis was only used as male, with negative results. These species and genera are partially isolated by a complex system of pre- and post-zygotic barriers. Knowledge of their nature would allow the breeder to devise strategies to put the genetic variability available in the group into a useful form. This revised version was published online in July 2006 with corrections to the Cover Date.