甘南地区歪头菜生殖分配对生殖产量的影响

采用现存生殖分配(Standing Reproduction Allocation)的方法研究甘南地区歪头菜(Vicia unijuga)生物量生殖分配。结果表明,不同生长年限植株在整个生长季中,各构件生物量占总生物量的比例随着季节变化表现为营养分配比重不断减少,生殖分配比重不断增加,但营养生物量分配比例占绝对优势,而在蕾期和花期用于有性生殖的生物量(蕾、花生物量)分配比例仅在10%左右;多年生歪头菜种群幼龄时期植株生殖生物量分配仍然随着生长年限的增加而增加,但生殖产量的生物量分配却表现出2年龄5年龄4年龄;2年龄植株蕾－花生物量转换比例和花－荚生物量转换比例分别为1∶1.17和1∶1.36,5年龄植株的分别为1∶0.94和1∶1.31,说明2年龄植株比5年龄植株有较高的生殖利用率,而5年龄植株落花、落荚现象明显。以上结果揭示出,植株对有性繁殖的小比例投资以及生殖转换中产生的生殖损失可能是导致该地区歪头菜种群有性繁殖体种子产量低的重要原因,而影响这一原因的因素可能是生长季过程中的环境干扰和养分竞争等问题。     

德系安哥拉兔的生长特性

德系安哥拉兔不仅以产毛量高、毛质好而著称,而且有生长迅速、体成熟早、体型大的特点。六月龄时已达成年体重的87.37％。母兔的初配可在此时进行,公兔可延迟一个月配种。四月龄与六月龄体重和成年体重的相关系数分别为0.505与0.508,这为德系安哥拉兔体重的早期选择提供了有利时机。     

The origin,evolution, cultivation,dissemination, and diversification of Asian and African rices

Summary Available evidences drawn from biosystematics, evolutionary biology, biogeography, archaeology, history, anthropology, paleo-geology and paleo-meteorology are pooled to reconstruct the series of events that led to the cosmopolitan cultivation of the Asian cultivated rice (O. sativa) and the regionalized planting of the African cultigen (O. glaberrima) in West Africa. The genus Oryza originated in the Gondwanaland continents and, following the fracture of the supercontinent, became widely distributed in the humid tropics of Africa, South America, South and Southeast Asia, and Oceania. The two cultivated species have had a common progenitor in the distant past. Parallel and independent evolutionary processes occurred in Africa and in Asia, following the sequence of: wild perennialwild annualcultivated annual. The weed races also contributed to the differentiation of the cultivated annuals. The corresponding members of the above series are O. longistaminata Chev. et Roehr., O. barthii A. Chev., O. glaberrima Steud., and the stapfii forms of O. glaberrima in Africa; O. rufipogon Griff., O. nivara Sharma et Shastry, O. sativa L., and the spontanea forms of O. sativa in Asia.The differentiation and diversification of the annuals in South Asia were accelerated by marked climatic changes following the last glacial age, dispersal of plants over latitude or altitude, human selection, and manipulation of the cultural environment.Cultivation of rice began in many parts of South and Southeast Asia, probably first in Ancient India. Cultural techniques such as puddling and transplanting were first developed in north and central China and later transmitted to Southeast Asia. Wetland culture preceded dryland culture in China, but in hilly areas of Southeast Asia, dryland cultivation is older than lowland culture. The planting method progressed from shifting cultivation to direct sowing in permanent fields, then to transplanting in bunded fields.Widespread dispersal of the Asian cultigen led to the formation of three eco-geographic races (Indica. Sinica or Japonica, and Javanica) and distinct cultural types in monsoon Asia (upland, lowland, and deep water). Varietal types changed readily within the span of a millenium, largely due to cultivators' preferences, socio-religious traditions, and population pressure. Genetic differentiation developed parallel to the ecologic diversification process.The African cultigen developed later than the Asian cultigen and has undergone less diversification. The wild races in South America and Oceania retain their primitive features mainly due to lack of cultivation pressure or dispersal.Both the African and Asian rices are still undergoing evolutionary changes at habitats where the wild, weed, and cultivated races co-exist.     

Evaluation of the germ plasm collection of safflower,Carthamus tinctorius L. VII. Variability of capitulum width and outer involucral bracts' dimensions

Summary A germ plasm collection of safflower, Carthamus tinctorius L., with about 900 lines from over twenty countries was evaluated in Utah, USA for head width and outer involucral bracts (OIB) dimensions, traits affected by both human and natural selection. The regional germ plasm pools contained considerable variability for these traits. Plants bearing short or long as well as narrow or wide OIB were well adapted. Geographical clines were detected for the means of OIB dimensions, indicating possible gene flow. The correlations of the OIB dimensions with yield, yield components, oil content and growing period were not instructive and at times very inconsistent. Primary head diameter varied considerably within the regional gene pools. Its correlations with yield/plant, number of heads/plant, seed weight and oil content were inconsistent. Capitulum width was positively and significantly correlated with the number of seeds per head. Head diameter, however, can vary considerably without affecting seed yield per unit area.     

一种新型集蔗器的结构设计及其有限元分析

集蔗器是甘蔗收割机中用来收集甘蔗的装置。通过总结前人所设计的集蔗器的优缺点,提出了一种新型集蔗机构—挡板式斜集集蔗器,并进行了结构设计、参数计算和三维建模;最后,为了验证所设计的集蔗器转轴的尺寸的合理性,通过有限元分析了软件ANSYS分析它在受外力情况下的变形情况和整体的应力分布情况。     

基于烟叶致香成分建立烤烟香型分类模型方法研究

为筛选出基于烟叶致香成分数据建立烤烟香型分类的最优模型,以便于较好地对烤烟的香型进行正确分类。首先对142 个烤烟烟叶样品中的45 个指标采用行业标准进行检测,然后采用逐步回归法筛选出14 个烟叶致香成分,依据这14 个指标采用判别分析法、Logistic 回归、高斯混合模型、分类树、K最邻近法、人工神经网络和支持向量机7种方法进行建模。通过对不同方法建立的模型采用100次随机抽取训练集样本和测试样本计算错误分类率,选择错误分类率较低的模型作为优选模型。结果表明,线性判别法和高斯混和模型建立的2 种香型函数能较好地对未知样品的香型进行正确分类,且效果较好（正确率可达90%以上）。研究筛选出的2种优选模型对于烤烟香型分类研究具有一定的应用价值。     

磷、钾对番茄可溶性碳水化合物分配的影响

以番茄苗为试验材料,研究了不同浓度磷、钾对番茄植株可溶性碳水化舍物分配的影响。结果表明：磷、钾亏缺处理45d后,与正常磷、钾处理相比,磷亏缺的植株冠根比下降,而钾亏缺的植株冠根比则上升。钾亏缺的植株叶片中,蔗糖、还原糖和总可溶性糖含量均表现为上升,根中则表现为下降。磷亏缺的植株叶片中,蔗糖、还原糖和总可溶性糖含量基本不变,而在根中则表现为不同程度的增加。在叶和根的总可溶性糖中,钾亏缺和磷亏缺的植株,根部总可溶性糖所占的比例分别为10．71％和45．65％,两者的对照分别为28．63％和33．11％。上述结果表明,钾和磷在光合产物的转运中所起的作用不同,植株中营养元素亏缺不同,干物质在不同部位的分配也不同。     

石头河水库灌区灌排信息管理决策支持系统

应用决策支持系统的原理,开发研制了陕西省石头河水库灌区灌排信息管理决策支持系统。该系统集成了数据采集与传输、数据库管理、水文预报、用水计划编制、兴利调度计划编制、系统维护6个子系统,于2002年石头河水库调度得到应用,编制了该水库年度供水计划、水库兴利调度计划和水库优化调度方案。     

小白菜小孢子培养胚状体的诱导

21个小白菜品种小孢子培养结果表明:适宜的花蕾长为2.5~3.5mm,花瓣与花药长度比为1/2~3/4;0.05~0.10 mg.L-1的细胞分裂素能促进小孢子胚的发生,高于此浓度的细胞分裂素对小孢子胚的产生有抑制作用,并使小孢子胚向畸形化发展;0.05mg.L-16-BA 0.10 mg.L-1NAA的配比可以明显提高成熟胚的比例。     

四大药用菊花功能成分的比较研究

为了比较4种药用菊花的品质特征,采用比色法测定总黄酮含量,HPLC测定绿原酸含量,GC-MS分析挥发油的成分.结果表明,贡菊、滁菊、亳菊和杭菊中总黄酮的含量分别为5.608%、4.619%、4.372%和3.017%;绿原酸含量分别为0.345%、0.207%、0.337%和0.131%;挥发油总量分别为0.243%、0.524%、0.388%和0.212%;GC-MS分离鉴定出的化合物中贡菊有18种,滁菊有46种,亳菊有35种,杭菊有6种.可见贡菊的主要功能成分较其他3种菊花含量高,并且具有较好的香气品质,认为贡菊可能不仅更适合药用,同时适于作为饮料、功能和保健食品的原料.