稻米综合品质与结实期气象因子的关系研究

通过全国１２个省的１３个试点进行的多品种多播期试验，研究证明结实期日均温是影响稻米综合品质的主要气象因子；两者间呈二次曲线关系；结实前、中期为决定稻米综合品质优劣的温度敏感时段。     

小麦灌浆期中光能供求关系模拟与南京地区合理株型的探讨

提出了一个数学模型,对南京地区(32.04°N,118.5°E)小麦籽粒灌浆期中光能供求关系作模拟,以消光系数的日变化为反映株型的指标,从叶水平角随灌浆日进程所应具有的动态表现探讨本地区辐射条件下的合理株型。利用模型对不同基因型的光能利用率作了具体分析。分析表明,在辐射资源不足的南京地区,小麦叶片的水平角随灌浆进程以有一个由直立而水平再至倒垂的动态过程为宜。     

两种不同穗型水稻品种灌浆期间物质生产特性的比较

选用直立穗型水稻品种辽粳326和弯曲穗品种奥羽316，在相同栽培条件下，比较两品种灌浆期间物质生产与分配、群体生长率(CGR)、净同化率(NAR)及与物质生产密切相关的叶绿素含量、叶面积指数(LAI)、比叶重等指标。结果表明，和弯曲穗品种奥羽316相比，直立穗品种辽粳326在灌浆后期仍能保持较强的物质生产能力，其抽穗后生产的干物质量占其生物产量的53．77％，比其经济产量高出12％。灌浆期间，直立穗品种辽粳326的比叶重较高，叶绿素含量较高，LAI下降较慢，各项生理指标优于弯曲穗品种奥羽316.抽穗后，直立穗品种辽粳326具有比弯曲穗品种奥羽316更强的生产能力．因而更符合高产栽培的需要。     

小麦籽粒灌浆特性分析

用Richards方程对新春8号等6个春小麦品种籽粒灌浆过程进行了拟合。结果表明,新春6号、新春9号和Geleng为典型的强、弱势粒异步灌浆型品种;新春8号、宁春30号和新陇麦15为典型的强、弱势粒同步灌浆型品种。异步灌浆型品种强、弱势粒起始势之间差异较大,强势粒进入灌浆盛期较弱势粒早;同步灌浆型品种强、弱势粒起始势之间差异不大。灌浆过程的前期、中期和后期3个阶段对总灌浆物质的贡献分别约占26％,45％, 29％,但所需的时间在强、弱势粒和品种间有较大差异。     

潍麦8号叶面积、穗粒重及其灌浆特点的比较研究

通过对不同类型品种的试验比较,研究潍麦8号旗叶面积、穗粒重及灌浆特点。发现潍麦8号具有高产多穗品种叶片小而上冲的特点,且灌浆速度快、穗粒重高。这解决了许多大穗品种穗大叶大、株型披散、易造成田间郁蔽的问题,证明较小的叶片能够提供较大的光合源。     

田间条件下控制玉米开花前后根系性状的QTL定位

在田间原位条件下,利用根系形态差异显著的自交系掖478和武312为亲本构建的BC4F3群体,采用改进的PLABQTL软件中的复合区间作图法对抽雄期（开花前10 d）和灌浆初期（开花后15 d）玉米根系性状的变化和地上部生物量进行QTL定位。并分析其遗传机制。结果表明,花前花后对根干重、总根长、侧根长、轴根长、轴根数等根系性状共检测出27个QTL,单个QTL贡献率为52%157%,其中在染色体臂602和1004区域同时检测到控制着地上部生物量、总根长、侧根长和轴根数等性状的QTLs,两个不同生育时期检测到的共同QTL共有8个。玉米花前花后控制根系生长的QTL因生长发育阶段不同而存在着特异性,而且对地上部生物量形成有重要贡献,这为了解田间条件下根系的生长发育和进一步进行遗传改良奠定了遗传基础。     

五个甘蓝自交系种株发育与开花结实特性研究

对5个甘蓝自交系(09335#、09336#、09337#、09338#、09340#)的植株形态、物候期、开花结荚、果实特征以及亲和性进行了鉴定。结果表明:09335#和09337#的各物候期早,植株生长势强,侧枝数多,花期授粉与蕾期授粉结荚率高、花期和蕾期亲和指数也较高,为较优良自交系;09336#和09340#居中,09338#较差。     

Analysis of the seed dispersal patterns of wild soybean as a reference for vegetation management around genetically modified soybean fields

There are concerns that genetically modified soybean might threaten the genetic diversity of the wild soybean populations that are distributed in East Asia because genetically modified soybean has no crossing barrier with wild soybean. A simple and effective method to prevent hybridization via pollen flow is spatial separation between the two species because their hybridization occurs only when they grow in close proximity. Therefore, the invasiveness of wild soybean needs to be known in order to secure the appropriate distances. As wild soybean seeds are dispersed mechanically by pod dehiscence, an experiment was conducted in which white sheets were placed on the ground, concentric circles were drawn around the parent plants, and the number of dispersed seeds within each 0.5 m‐wide zone were counted. About 40% of the produced seeds were dispersed and the number of dispersed seeds gradually declined as the distance from the parent plants increased. The model that explained the relationship between the number and distance of the dispersed seeds was produced by using a generalized linear model procedure. More than 95, 99, and 99.9% of the produced seeds stayed within 3.5, 5.0, and 6.5 m after natural pod dehiscence. Knowing these values is useful for evaluating the level of invasive risk by mechanical seed dispersal. The goal of the work is to efficiently and deliberately prevent hybridization by isolating genetically modified soybean fields and wild soybean populations by vegetation management, including weeding and setting up specific‐width buffer zones.     

Ozone sensitivity of Phaseolus vulgaris in relation to cultivar differences,growth stage and growing conditions

Exposure of Phaseolus vulgaris cv. Lit to ambient ozone caused a 14% pod yield reduction in 1994. This yield loss was assessed by comparing plants that were protected against ozone by treatment with EDU (ethylenediurea) with unprotected plants, both cultivated in pots with a continuous water supply. The plants had experienced an AOT40 of 8135 ppb.h during their growth. However, plant response to ozone depends on a large number of environmental and plant-specific conditions. Visible injury increased mainly after flowering and was much less severe on soil-grown bean cultivars (Lit, Stella and Groffy) not receiving additional water. Ozone fumigations in closed chambers before or after flowering proved that the growth stage during which the plants are exposed also plays a very important role with regard to injury development. Plants seem to be more susceptible during the generative growth stage and the relative cultivar sensitivity was related to the developmental stage during fumigation. However with regard to yield effects the timing of the ozone exposure seems to be less important.     

Nitrogen metabolism in flag leaf and grain of wheat in response to irrigation regimes

Although scarcity of irrigation water is one of the key limiting factors for wheat production in many regions of the world, by using partial irrigation at strategic times during the growing season, it might be possible to enhance productivity. We measured the changes in various parameters related to nitrogen (N) metabolism in flag leaf and grain of wheat (Triticum aestivum L.) plants (cv. Jinan 17 and Lumai 21), which were subjected to five irrigation regimes until physiological maturity. Severely deficient or excessive irrigation during grain filling decreased the photosynthetic rate (A), the concentrations of N, free amino acid, and soluble protein, as well as the activities of nitrate reductase (NR) and glutamine synthetase (GS) and increased malondialdehyde (MDA) accumulation and endopeptidase (EP) activity, though grain protein concentration might mainly depend on genotype. The activities of NR and GS were significantly positively correlated with A, but those of EP were significantly negatively correlated with A. The results indicate that while severe water stress aggravates the adverse effect on nitrogen metabolism, excessive soil moisture is also not useful during the grain‐filling stage, resulting in lower grain yield and quality. Our results suggest that applying an optimal irrigation regime in wheat fields still plays an important role in the improvement of grain yield and quality.