麦前深松对夏玉米土壤物理性状和生长特性的影响

为探明华北地区深松耕作方式对夏玉米生育期土壤物理性状和水分利用效率的影响,在河南省新乡采用冬小麦播前深松耕作(PS)、传统旋耕(CK)2种耕作方式,对夏玉米各生育期间的土壤粒径组成、容重、土壤紧实度、夏玉米生长发育指标及水分利用效率等进行了研究。结果表明:PS处理下土壤粒径组成无明显变化,全生育期PS较CK处理0—40cm土层土壤容重降低0.63%~3.85%,孔隙度提高0.27%~3.67%;拔节期PS较CK处理20—30,30—40cm土层土壤紧实度显著降低37.76%,22.26%;全生育期PS处理的土壤含水率、夏玉米株高、叶面积指数、干物质积累量均高于CK,产量提高了9.50%,穗长和穗粒重提高了4.18%和6.50%(p0.05),水分利用效率提高5.08%,节水增产效果显著。     

Morphological disparities in the epidermal and anatomical features of the leaf among wild Brassica juncea populations

In the present article, we investigated the epidermal and anatomical features of 10 wild Brassica juncea populations with different susceptibilities to glyphosate in detail. The characteristics of the leaf surface and anatomy could affect the efficacy of glyphosate uptake in weeds through the influence of its adherence and penetration. Our results showed that herbicide-resistant wild populations generally had greater leaf thickness, adaxial cutin thickness, and trichome density in the upper epidermis, but lower spongy tissue thickness and vascular bundle numbers, as compared with the susceptible populations, suggesting that differences in morphological traits among populations might contribute to their variable response to glyphosate. The possible morphological involvement in the differential susceptibility of wild B. juncea populations to glyphosate also was discussed.     

3种阔叶树育苗技术及苗木生长规律研究初探

通过对闽楠，蓝果树，东京野茉莉的育苗试验，研究苗木生长规律，掌握生理生物学特性。     

Allele Types of Rc Gene of Weedy Rice from Jiangsu Province,China

Weedy rice(Oryza sativa f. spontanea), the predominant type of which has a red pericarp, seriously inhibits growth and yield of direct-seeded rice in Jiangsu Province, China. In this study, we randomly selected 10 weedy rice accessions from 10 plots in Jiangsu, and then sequenced the full lengths of their Rc genes(approximately 6.4 kb). In addition, we collected 166 different full-length Rc genes in the Oryza genus from the literature and from GenBank. A collinearity sequence analysis showed that the 10 weedy rice accessions from Jiangsu all had the same wild-type allele of the Rc gene. Single nucleotide polymorphisms indicated that the nucleotide polymorphisms(π = 0.19) and the proportion of segregation sites(θw = 0.28) of the Rc genes in the 10 weedy rice accessions from Jiangsu were higher than those in 56 weedy rice accessions from USA(π = 0.09 and θw = 0.07). Haplotype and phylogenetic analyses showed that the Rc genes of weedy rice accessions from Jiangsu were not revertants of the rc gene found in Asian cultivated rice(O. sativa) varieties with white pericarp. In addition, Rc gene sequences of the rice varieties Lvdao from Lianyungang, Jiangsu and Tangdao from Anhui were more similar to those of cultivated rice than to the weedy rice from Jiangsu. These findings support the continued quarantine of weedy rice and clarify the evolutionary mechanism of the red pericarp found in the weedy rice of Jiangsu.     

农村经济综合数据分析系统研究与开发

以山西省为例,研究开发了区域农村经济数据分析系统,利用数据仓库、数据挖掘、模型分析、空间分析等技术,将海量农村经济数据有序组织起来,实现对研究区域农村经济相关信息进行从简单信息查询、定制分析、模型分析、专题分析、空间分析并及时发布等系统功能,提高农村经济研究效率,为政府快速、有效决策提供科学参考。     

60Co-γ射线辐射对香福禄考发芽率及幼苗长势的影响

用60Co-γ射线辐射香福禄考种子,观察其发芽率和幼苗生长情况。结果表明:30、60 Gy辐射对发芽率有促进作用,60、70 Gy辐射则对幼苗生长有很好的促进作用。     

沙地葡萄引种栽培试验报告

经过历时8年的栽培试验,对16个引进葡萄品种进行了详尽的观察测定,结果表明,87 1、红地球、 藤稔、夕阳红、瑰香怡表现优秀,皇冠、里扎玛特、红富土、黑奥林、先锋、巨锋表现良好,京亚、紫玉、康太、康能无核 表现较差。     

烟草生长的二次非线性示踪动力学模型

为研究示踪剂转移的非均匀动力学过程,在0时刻向烟草一次性引入某种示踪剂后,根据烟草对这种示踪剂吸收快、排除慢的情况,假设烟叶和烟茎对这种示踪剂的吸收是二次函数关系,而对这种示踪剂的排除是线性函数关系,建立了烟叶的单库室Logistic示踪模型和烟叶一烟茎的两库室二次非线性耦合示踪动力学模型.对2种模型的定性结果分析表明...     

土壤杂草种子库与杂草综合管理

土壤杂草种子库是农田杂草发生危害的主要根源,种子库的动态变化规律对于杂草的综合管理具有非常重要的意义。目前研究表明,杂草种子库的密度和组成变化很大,与田间杂草群落具有密切的联系。杂草种子库时刻处于输入和输出的动态变化之中。耕作方式影响杂草种子在土壤中的垂直分布,从而间接影响种子库的密度和种类组成;作物轮作使杂草的生存环境趋于多样化,能够限制某些对单一种植系统有着良好适应性的杂草种类的生长,作物轮作对杂草种子库种类组成和丰富度的影响要大于耕作方式;杂草管理措施能够大大降低田间杂草的结实,从而减小杂草种子库的规模。随着人们对除草剂使用和环境安全问题的日益关注,发展基于生态规律的杂草管理措施越来越受到人们重视,结合近几年国内外的研究进展,作者提出了杂草种子库今后的一些新的研究发展方向。     

温度和盐度对吉富品系尼罗罗非鱼受精率和孵化率的联合影响

采用中心复合设计和响应曲面方法研究了温度(T,℃)和盐度(S)对吉富品系尼罗罗非鱼人工受精率(FR,％)和孵化率(HR,％)的综合影响.设定的温度范围为20～34,盐度范围为0～18.建立了温度、盐度与受精和孵化之间关系的定量模型,并通过分析明确了温度与盐度的最优组合.结果表明,吉富罗非鱼在温度与盐度较高或较低范围内受精率与孵化率都处于较低水平.温度和盐度的一次与二次效应对受精与孵化均有极显著的影响(P＜0.01).温度与盐度二者间协同效应不显著(P＞0.05).建立了吉富罗非鱼受精率与孵化率的多项式方程,复相关系数分别达到了0.957 8和0.960 1 (P＜0.01),可以用于预测吉富罗非鱼的受精率和孵化率.利用统计优化技术明确,在温度27.14℃,盐度8.95时,罗非鱼最佳的受精率为80.8％,孵化率为77.63％.本研究旨在考察温度与盐度同时变化对吉富罗非鱼受精率与孵化率的影响,探讨最佳温度－盐度组合以增加吉富罗非鱼苗种产量.