一个水稻抽穗期主基因Hd(t)的遗传分析及分子定位

从缙恢10/R21的杂种后代中发现了一个抽穗期稳定遗传的迟熟恢复系N91(110~114 d)，以早熟不育系金23A(89~94 d)作为杂交和回交亲本，获得的F₂和BC₁F₁群体抽穗期均表现双峰分布，χ²检测表明其抽穗期受一对主基因控制，暂命名为Hd(t)。在400多对SSR引物中筛选出5对在早熟基因池和迟熟基因池中表现差异的引物，进行单株验证，用回交群体进行基因定位，发现位于第7染色体长臂末端的SSR标记RM1364和RM3555与Hd(t)连锁，遗传距离分别为32.7 cM和22.5 cM。在目标区域进一步合成8对SSR引物，将Hd(t)基因定位在RM22143与第７染色体末端之间，与RM22143相距12.9 cM。该结果为Hd(t)基因的精细定位、分子标记辅助育种和基因克隆奠定了基础。     

氮硫交互作用对小麦苗期生长和养分吸收的影响

通过基质盆栽冬小麦，研究了氮硫交互作用对小麦苗期生长及养分吸收的影响。研究结果表明，氮、硫对苗期小麦的生长都有一定影响，氮的增产效果远大于硫，当氮肥用量为200mg/盆时，小麦生物量的最大增产幅度89％；在低氮水平下，硫肥的增产效果最佳，最高可增产125。硫肥的施用可以提高苗期小麦植株体内硫的累积量，在氮素胁迫的情况下最为显著，可提高1倍以上；同时降低植株体内氮的累积，但降低幅度不大。氮素充足时，地上部与地下部生物量之比为2.4-3.9，氮素胁迫条件下，小麦的地上部和地下部的生物量相当，说明氮素养分不足时，小麦合成的有机物质更倾向于分配给根系，促进根系的生长，这可能是小麦抵抗胁迫环境条件的生理机制之一。     

新时期稳定高校管理队伍的几点思考

2007年被教育部定为“高等学校管理年”,管理出质量,管理出效益。一流的大学必须要有一流的管理,建设一支稳定、精干、高效的管理队伍对高校的改革和长远发展至关重要。重视和解决目前高校管理队伍中存在的种种问题,努力构建和稳定一支高素质的管理队伍,是高校可持续发展的必然要求。     

Influence of race and post infection temperature on two components of partial resistance to wheat leaf rust in seedlings of wheat

Summary Components of partial resistance, infection frequency and latency period, were determined in 71 winter and spring wheat genotypes in the seedling stage, after infection with three races of leaf rust (Felix 3B, Clement B and Betuwe 85C) at three different day/night temperature regimes (24/18°C, 18/12°C and 12/6°C). The genotypes were split into two groups and two separate experiments were carried out. Five genotypes, SVP 84039, Akabozu, Banco, BH 1146 and Orso, conferred a low infection frequency and a long latency period and Westphal 12A a long latency period, indicating a relatively high level of partial resistance. The correlation coefficient between infection frequency and latency period was low. Race-specificity was not found. There was a significant temperature effect on the latency period. In the second experiment the temperature x genotype interaction was significant. Temperature-response functions of transformed data demonstrated that the latency periods of four relatively resistant genotypes, Westphal 12A, Banco, BH 1146 and Orso and of Sarno and Mirela were most sensitive to temperature. The range between the genotypes with the longest and the shortest latency period was highest at 12°C. Therefore, low temperature regimes are preferred to distinguish differences in level of partial resistance.     

水稻籽粒直链淀粉及蛋白质含量对孕穗期弱光胁迫的响应

以2个不同直链淀粉含量的水稻品种为材料，研究了孕穗期遮光（遮光率50％）对水稻籽粒直链淀粉及蛋白质含量的影响。结果表明，遮光与对照的籽粒直链淀粉的积累过程均可以用二次曲线回归方程模拟，因此其积累过程可以大体分为2个阶段，即快速增长阶段，变化相对平稳阶段；遮光的籽粒直链淀粉和蛋白质含量变化速率具有波动性，即时而高于对照，时而低于对照；遮光对2个品种籽粒直链淀粉及蛋白质含量的影响完全相反；成熟籽粒直链淀粉与蛋白质含量呈负相关性，相关系数r=-0．81786，表明孕穗期遮光可能会对稻米的食味品质产生不利影响。     

播期对玉米早代自交系田间抗病性的影响

对1998－2000年4月中下旬（春播）和6月上旬（夏播）种植的1607份玉米早代系进行田间自然抗性鉴定表明：播期对玉米早代系田间抗病性具有很大的影响，玉米早代自交系大斑病和粗缩病以春播发生较重，而小斑病和茎基腐病以夏播发病较充分。因此，在鉴定玉米早代系田间抗性时应根据鉴定病害对象安排在不同播期进行。     

对两个亚热带优质蛋白玉米群体的适应性混合选择研究：Ⅱ.相关响应

在两个源于亚热带的优质蛋白玉米（ＱＰＭ）群体，中群１３和中群１４中，对早开花性状进行４轮混合选择，籽 粒产量和植株形态特征发生显著的相关响应。１９８９至１９９１年在北京作的４年评价试验中，中群１３和中群１４平均每轮每亩籽粒产量分别增加４１．８（２８．７％）和４１．５ｋｇ（２９．０％）。与线性回归响应（ｂ＝３７．４和４０．４ｋｇ）相吻合。１９９１年在北京、济南、武功、成都和海南三亚作的５点联合试验中     

Mature plant and tissue resistance in the groundnut-peanut bud necrosis virus system

Summary Leaves and plants of different ages of a susceptible and two resistant groundnut genotypes were mechanically inoculated with peanut bud necrosis virus, and the percentage of plants with systemic symptoms (incidence) and the incubation period were determined. The incidence decreased sharply in all three genotypes with the age of the inoculated leaves and plants. The incubation period increased with the age of leaves and plants. Apparently, only young tissue of young plants is susceptible, while mature tissue and plants are highly resistant. This mature tissue and plant resistance occurs irrespective of the susceptibility level of the genotype to peanut bud necrosis virus, however, it develops earlier in the resistant than in the susceptible genotypes.Abbreviations IP₅₀ incubation period - PBNV peanut bud necrosis virus - TSWV tomato spotted wilt virus