Pollen development and floral morphology of Populus pseudo-simonii

Pollen development and floral morphology of Populus pseudo-simonii were investigated by stain-squashing and anatomical techniques. It took approximately 16 days for the pollen to develop from pollen mother cells to mature pollen in the greenhouse. Meiosis of pollen mother cells was regularly applied and completed by a process of simultaneous cytokinesis. Pollen development was considerably asynchronous. The meiotic division was initiated at the bulgy middle position of the flower bud and proceeded towards t...     

水稻颖花外稃表面双峰乳突扫描电镜观察

用扫描电镜对普通野稻和普通栽培稻的籼粳两亚种外稃表面双峰乳突的结构作了比较观察。根据双峰距、垭深度、峰角度等特征,把双峰乳突分为两种基本类型。籼稻为锐型,粳稻为钝型,普通野稻为中间型。     

绢丝昆虫柳天蚕细胞遗传学的研究

本文利用改良空气干燥制片法,首次对柳天蚕(Actias Selene Hubner)的染色体数目、形态及减数分裂过程进行了研究。结果表明,柳天蚕雌雄染色体数目均为n=31,呈颗粒状。其性型为xx-xy(或zz—zw)型。在双线期及终变期,雄比雌具有更为明显的交叉现象。继而对雌双线期染色体的绝对长度、相对长度进行了测算,结合染色粒等指标,初步进行了雌蚕组型排列,并得出了柳天蚕雌双线期染色体组型的雏型,对于开辟野蚕类的核型研究,充实蚕类细胞遗传学内容,具有一定的意义。     

贵州务川黑牛线粒体DNA D-loop区全序列分析

务川黑牛是贵州省新近发现的独特地方品种,其起源和系统地位尚存争议.为了解其遗传多样性及遗传背景,该研究测定了22头务川黑牛个体的线粒体D-loop区全序列.结果表明:22头务川黑牛个体中存在51个核苷酸多态位点,碱基组成中A+T含量大于G+C含量;共检测到11种单倍型,核苷酸歧异度(π值)为5.475%,单倍型多样性Hd为(0.909±0.044),表明务川黑牛线粒体DNA D-loop高变区具有丰富的多态性;系统分析表明务川黑牛同时受普通牛和瘤牛的影响.     

油菜不同氮素籽粒生产效率品种氮素积累与分配特征

2007—2008年度以98个甘蓝型常规油菜品种(系)为材料, 在不施氮肥(N₀)和纯氮150 kg hm^–2 (N₁) 2个处理下, 通过测定成熟期不同器官干重、氮素含量, 采用组内最小平方和动态聚类方法对供试品种的氮素籽粒生产效率(NUEg)聚类并分析其氮素积累与分配差异。结果表明, 不同品种氮素籽粒生产效率差异较大, 类型间差异极显著。不同类型品种随着氮素籽粒生产效率增加, 产量增加。相关分析表明, 氮素籽粒生产效率与成熟期氮素吸收总量之间相关不显著(r_N0= –0.0245, r_N1= –0.1131), 与成熟期茎秆氮素分配比例(r_N0= –0.5941^**, r_N1= –0.4141^**)和果壳氮素分配比例(r_N0= –0.6007^**, r_N1= –0.5374^**)呈极显著负相关, 与籽粒氮素分配比例(r_N0= 0.7954^**, r_N1= 0.7239^**)呈极显著正相关;与成熟期总籽粒数呈极显著正相关(r_N0= 0.5945^**, r_N1= 0.5412^**)。氮素籽粒生产效率和氮素吸收总量对产量都有显著影响, 油菜品种的选育应在一定氮素吸收总量基础上, 促进后期氮素从营养器官向籽粒中输送, 提高氮素籽粒生产效率, 从而达到高产和高氮素利用效率的统一。     

黄麻染色体组型研究

本文比较研究了圆果黄麻“粤圆5号”和长果黄麻“翠绿”的染色体组型。结果是:圆果黄麻和长果黄麻的染色体组型均为 K(2n)=14=12M+2M~(sat),即其染色体均属于中部着丝粒染色体。前者的第5对染色体为随体染色体,后者的第6对染色体为随体染色体。     

Identifying future research needs in landscape genetics: where to from here?

Landscape genetics is an emerging interdisciplinary field that combines methods and concepts from population genetics, landscape ecology, and spatial statistics. The interest in landscape genetics is steadily increasing, and the field is evolving rapidly. We here outline four major challenges for future landscape genetic research that were identified during an international landscape genetics workshop. These challenges include (1) the identification of appropriate spatial and temporal scales; (2) current analytical limitations; (3) the expansion of the current focus in landscape genetics; and (4) interdisciplinary communication and education. Addressing these research challenges will greatly improve landscape genetic applications, and positively contribute to the future growth of this promising field. Participants of the Landscape Genetics Research Agenda Workshop, held at the 2007 World Congress of the International Association of Landscape Ecologists (IALE), in Wageningen, The Netherlands: Paul Arens, Pascal Campagne, Virginia H. Dale, Alfredo G. Nicieza, Marinus J. M. Smulders, Edoardo Tedesco, Hongfang Wang, Tzeidle Wasserman.