莜麦与野红燕麦杂交的细胞遗传学研究

为将野红燕麦９Ａｖｅｎａ ｓｔｅｒｅｌｉｓ Ｌ）的高蛋白,抗蚜、抗锈病等优点导入莜麦（Ａ ｖｅｎａ ｕｎｄａ Ｌ）,进行莜麦与野红燕麦的杂交研究,Ａ,ｎｕｄａ×Ａ．ｓｔｅｒｅｌｉｓ杂交（４８朵小花）,获得１个幼胚和４粒种子,杂交结实率１０．４％,Ｆ１自交结实率４８．１％,杂种Ｆ１在穗型,外秀,芒性,茎节部性状等方面与母本莜麦存在显著差异,来自野红燕麦的野生性状,如外孚绒毛,曲强芒,落粒性等均说明Ｆ１     

苹果属植物种内和种间无融合生殖能力研究

】根据去雄套袋的座果率,用方差分析法研究了苹果属７个无融合生殖种类的种内和种间差异。结果表明,种间只有小金海棠与湖北海棠、三叶海棠和丽江山定子的差异极显著。在湖北海棠的４个类型中,南坪湖北海棠、盐源湖北海棠和平邑甜茶与丽江山定子差异显著,其余种间差异均不显著。湖北海棠不同倍性和来源的４个类型间无显著差异。     

Transfer of resistance to race 2 of Plasmodiophora brassicae from Brassica napus to cabbage (B. oleracea ssp. capitata). III. First backcross and F2 progenies from interspecific hybrids between B. napus and B. oleracea ssp. capitata

Summary The first backcross and F₂ progenies from triploid F₁ and tetraploid F₁ hybrids between B. napus and 2x and 4x B. oleracea ssp. capitata (cabbage) were studied for their general morphology, resistance to race 2 of the clubroot pathogen, chromosome number and meiotic chromosome behavior. No linkage was apparent between resistance and the major morphological characters. Unreduced gametes played a large part in the successful formation of seed of the B₁ and F₂ progeny. B₁ plants with low chromosome numbers were selected for use in recurrent backcrosses. The potential use of anther culture to extract gametic progenies from resistant B₁ and F₂ plants with higher chromosome numbers was suggested. The presence of homoeologous pairing observed in all the plants is considered advantageous for selecting suitable progeny in later generations.     

Jatropha tanjorensis Ellis & Saroja, a natural interspecific hybrid occurring in Tamil Nadu, India

Jatropha tanjorensis Ellis & Saroja, a species found abundantly in Tanjore, Pudukottai, Trichirapalli and Ramnad districts of Tamil Nadu state, India and grown as a fence plant showed intermediacy in phenotypic characters of J. curcas L. and J. gossypifolia L. A detailed survey at its place of occurrence supplemented with data employed from cytological and peroxidase isozyme studies revealed that J. tanjorensis is a natural interspecific hybrid between these two species. Since there was no seed set, propagation through tissue culture using leaf discs was attempted.     

毛白杨起源的细胞遗传学研究

对毛白杨(PopulustomentosaCarr.)花粉母细胞减数分裂观察发现,其同源染色体联会较差,在终变期、中期Ⅰ可见到出现频率较高的单价体,在后期Ⅰ、末期Ⅰ亦可经常见到落后染色体的存在,证明部分同源染色体间存在一定程度的异质性,即毛白杨属杂种起源.进一步依据毛白杨、新疆杨和它们的杂种毛新杨染色体的联会情况及花粉育性等推断,银白杨或新疆杨有可能作为起源亲本之一参与了毛白杨种的形成.     

种间杂交狗牙根足球场草坪的建植与管理技术研究

本文系统地总结了 Ｔｉｆｗａｙ 足球场草坪的建植和日常养护管理技术。证明种间杂交狗牙根品种 Ｔｉｆｗａｙ 是成都地区建植足球场的理想品种,值得大力推广。     

栽培大豆×半野生大豆主要农艺性状的遗传变异及回交改良

对６个栽培大豆与半野生大豆杂交组合及９个回交组合进行了分析。结果表明：大豆品种间杂种优势是普遍存在的,而且主要表现在产量性状上,百粒重的杂种优势及超亲优势为负值,超亲优势的表现与杂种优势的表现基本相同。杂种后代植株高、分枝多、籽粒小是半野生大豆在育种工作中利用的障碍。以有限性品种做回交亲本对种间杂种后代降低株高效果最佳,亚有限品种次之,无限品种效果最差。为克服杂种后代的小粒性,必须用大粒亲本进行回交并进行定向选择。在蛋白质含量上用高蛋白品种进行连续回交,可逐年提高杂种后代蛋白质含量     

地锦和五叶地锦种间杂交不亲和性初步研究

将地锦和五叶地锦杂交,未能获得杂交种。对人工辅助自交和杂交后,花粉萌发和花粉管生长情况进行了荧光显微观测。观察发现：人工辅助自交后,花粉粒可在各自柱头表面正常萌发,花粉管可伸入花柱内。将地锦和五叶地锦杂交时,多数花粉粒不能在柱头表面萌发,或者花粉管呈卷曲、先端膨大、破裂等异常现象。授粉后2～48h的花柱中,未观察到花粉管。由此推断,地锦和五叶地锦之间的不亲和发生在柱头表面。     

菊属种间杂种的鉴定

利用RAPD技术、细胞学及形态学手段对菊属种间杂种进行鉴定。RAPD标记结果表明：杂种表现出父本特异带或双亲均不具备的新谱带。细胞学鉴定结果表明：杂种染色体数目为亲本平均值。形态学性状观察、统计表明：大多数杂种性状介于双亲之间,但部分性状则较为明显地相似于多倍体;部分杂种表现父本特异性状,或出现双亲所不具备的新性状;二倍体野生种与栽培菊花杂种形态分离广泛,说明多倍体栽培菊花具复杂的遗传背景。     

The influence of pelagic habitat selection and interspecific competition on productivity of juvenile walleye pollock (Theragra chalcogramma) and capelin (Mallotus villosus) in the Gulf of Alaska

Here we investigate processes affecting productivity of capelin and walleye pollock in the Gulf of Alaska. We examine pelagic habitat selection by comparing the distribution of juvenile fish and their prey with oceanographic properties and we evaluate the potential for interspecific competition by comparing diets and measures of foraging. The primary field study was conducted in Barnabus Trough, Kodiak Island, Alaska, during September 2005. The distribution of fish was assessed acoustically and trawls were used to collect individual fish for stomach content analyses. Physical and biological data were collected with conductivity–temperature–depth probes and zooplankton tows. Age‐0 pollock were distributed in cool waters offshore of a mid‐trough front, coincident with the distribution of euphausiids, their preferred prey. In contrast, capelin and their prey (copepods) were distributed throughout the trough. We observed that sympatric capelin (occurring with pollock) often had reduced foraging success compared to allopatric capelin (occurring alone). Results of a bioenergetic model also suggest that the exclusion of capelin from foraging on euphausiids can have negative consequences for capelin growth.