徐淮棉区杂交抗虫棉早衰原因及预防

通过对科棉1号苗情考察与试验对比,分析杂交抗虫棉早衰原因,提出其预防措施.     

不同套袋、除袋时期对苹果质量影响

对沂蒙山区红富士苹果不同套袋时期和不同除袋时期、方法对果实品质的影响以及不同摘袋时间对日灼率的影响进行了研究.结果表明:沂蒙山区红富士苹果5月25日～6月5日是套袋的最佳时期,10月3～9日是除外袋的最佳时期,去除内袋适宜时间为外袋摘除后4～6d.     

葡萄酒渣饲用研究概况

葡萄渣是一种潜在的饲料资源:国外开展饲用研究较早,而国内研究甚少。本文对十几年来国内外有关研究进行了概括,总结出其在不同畜禽日粮中的适宜用量。     

家兔对非蛋白氮利用研究概况

本文对有关家兔对非蛋白氮利用试验研究进行了综述,对其利用效果进行了概括。     

草莓试管快繁的研究

本试验对草莓的试管快繁技术进行了研究。结果表明:诱导草莓茎尖分化的最适培养基是MS+BA(6——苄基腺嘌呤)0.1～0.5mg·L~(-1),每30天可繁殖一代,增殖15倍,其中50％可用于生根;草莓生根培养基以不加任何激素的MS为最好,接种7天就可生根,生根率达100％;当根长1cm左右时,将草莓试管苗栽入蛭石中,控制温度和湿度,成活率可达90％以上。     

QTL mapping for seedling traits under different nitrogen forms in wheat

The uptake and utilization of nitrogen (N) by plants are affected by the different forms of N in the soil. In this study, eight morphological traits at the seedling stage were investigated using a set of recombinant inbred lines (RILs). Three hydroponic culture experiments were conducted using three different NO₃ ^?/NH₄ ⁺ ratios (T1 at 50/50 %, T2 at 100/0 % and T3 at 0/100 %). The investigated traits in T2 and T1 were significantly higher than T3 in all three experiments, indicating that NO₃ ^? promoted or NH₄ ⁺ suppressed the production of biomass. Comparing T1 with T2, NO₃ ^? significantly increased the values of root fresh weight (RFW), total fresh weight (TFW) and root dry weight (RDW) and significantly decreased shoot dry weight (SDW). A total of 147 quantitative trait loci (QTLs) for the eight traits were detected on 18 chromosomes (except 2A, 3D and 4D). Among them, 16 QTLs (QRfw-1A, QRfw-1D, QSfw-1D, QSfw-2B.1, QTfw-1A, QTfw-1D, QRsfw-2B, QRsfw-3B.1, QRdw-1A.1, QRdw-1A.2, QSdw-6B.1, QSdw-7A.1, QTdw-1A.1, QRsdw-1A.1, QRsdw-5A.1 and QRsdw-7A.1) were detected in more than three of the nine treatment–experiments, and most of the 16 QTLs made large contributions of approximately 15 %. Surprisingly, QRsfw-4A.1 and QRsfw-4A.2 explained as much as 47.9 and 55.5 % of the phenotypic variation, respectively. Thirteen important QTL clusters (C1-C13) with more than four QTLs and involving 66 QTLs (44.9 %) were mapped on chromosomes 1A, 1D, 2B, 2D, 4A, 4B, 5B, 5D, 6B, 7A and 7B.     

桑花叶萎缩类病毒的检测与序列多态性分析

为调查桑花叶萎缩类病毒的多态性,通过RT-PCR技术分离了安康地区桑花叶型萎缩类病毒,并对其基因组进行了克隆测序和序列分析。结果获得4 个MMDVd变体,核苷酸长度为356 nt 或357 nt,GC含量均约51%,Mfold网站预测二级结构两端为分枝状结构,其中约有58%的碱基配对。     

A review of the sampling theory of comprehensive forest resources monitoring

Sampling is a key technique in comprehensive forest resources monitoring. The history of the sampling survey was briefly reviewed and sampling theories were classified and compared in detail. On the basis of that, the application of different sampling methods in comprehensive forest resources monitoring was illustrated in accordance with the sampling classification of Michael Köhl et al. Improvement of the sampling system in China was discussed to meet the new requirements of forest monitoring.