QTL Mapping for Stalk Related Traits in Maize (Zea mays L.) Under Different Densities

Stalk related traits, comprising plant height (PH), ear height (EH), internode number (IN), average internode length (AIL), stalk diameter (SD), and ear height coefficient (EHC), are significantly correlated with yield, density tolerance, and lodging resistance in maize. To investigate the genetic basis for stalk related traits, a doubled haploid (DH) population derived from a cross between NX531 and NX110 were evauluated under two densities over 2 yr. The additive quantitative trait loci (QTLs), epistatic QTLs were detected using inclusive composite interval mapping and QTL-by-environment interaction were detected using mixed linear model. Differences between the two densities were significant for the six traits in the DH population. A linkage map that covered 1 721.19 cM with an average interval of 10.50 cM was constructed with 164 simple sequence repeat (SSR). Two, two, seven, six, two, and eight additive QTLs for PH, IN, AIL, EH, SD, and EHC, respectively. The extend of their contribution to penotypic variation ranged from 10.10 to 31.93%. Seven QTLs were indentified simultaneously under both densities. One pair, two pairs and one pair of epistatic effects were detected for AIL, SD and EHC, respectively. No epistatic effects were detected for PH, EH, and IN. Nineteen QTLs with environment interactions were detected and their contribution to phenotypic variation ranged from 0.43 to 1.89%. Some QTLs were stably detected under different environments or genetic backgrounds comparing with previous studies. These QTLs could be useful for genetic improvement of stalk related traits in maize breeding.     

波尔山羊与本地山羊杂交效果研究

通过繁殖性能、生长发育及屠宰测定分析,对波尔山羊与本地山羊杂交效果进行研究。结果表明,波尔山羊与本地山羊杂交能显著提高本地山羊产羔率、羔羊成活率、生长速度、屠宰率和净肉率,改良效果明显。     

刘歆的《周礼》学及其在两汉之际的传承谱系

两汉之际是《周礼》学的奠基和发轫时期。刘歆是《周礼》学的奠基人和开拓者。约略说来刘歆对《周礼》学发展所做的贡献,主要有如下三端：首先,刘歆在与其父刘向受诏校理秘府图书时,不仅将《周官》（《周礼》）这部几乎不为世人所知的典籍著录于《七略》之中,而且还“独识”《周礼》的价值,顶住各方面的压力,不遗余力地向学术界推介这部在秘府之中新发现的典籍。其次,《周礼》一书于王莽当政时被立于学官、设博士主要应归功于刘歆的推动。复次,刘歆不仅研治《周礼》,撰著《周官传》四篇,而且还广收门徒,传授《周礼》之学。两汉之际著名经学家杜子春、郑兴、贾徽、郑众、贾逵及卫宏等人都曾直接或间接地师从刘歆学习过《周礼》。他们或是刘歆的弟子,或是刘歆的再传弟子,都出于刘歆的《周礼》学传承谱系。他们在《周礼》研究领域都做出了重要贡献,从而使《周礼》学逐步发扬光大。     

森林与可持续发展

可持续发展是人类社会全方位的发展、进步、优化选择,而森林是可持续发展的保障。当今,水土流失,耕地退化,土地沙化,水资源不足等诱发的生态环境恶化,是制约我国实施可持续发展战略的障碍因素,以及“温室效应”,无不与森林有关,最好,最有效的方法是造林种草。当今全世界人民齐声大合唱的最强音,是保护环境,保护森林。森林,是民族繁荣的标志。     

衡观35小麦丰产稳产性分析及增产途径探讨

对衡观35小麦6 a计90点次的区试和示范的丰产稳产性进行了分析,并对不同种植区域的增产途径进行了探讨。结果表明:(1)衡观35是1个矮秆大穗、抗病抗倒、高产广适型小麦品种,产量稳定在7 500~8 250 kg/hm2,并具有9 750~10 500 kg/hm2的产量潜力;(2)相关分析和通径分析结果表明,不同种植区域的产量结构不同,黄淮南片麦区三因素顺序为千粒重单位面积穗数穗粒数,冀中南麦区三因素顺序为穗粒数千粒重单位面积穗数;(3)单位面积有效穗数对产量的直接作用最大,在黄淮南片冬麦区、冀中南冬麦区通径系数分别为0.761 3和0.539 8;(4)在保证630万~675万穗/hm2群体结构的基础上,黄淮南片麦区主攻千粒重,冀中南麦区重点增加穗粒数,可发挥该品种的最大丰产潜力。     

新疆棉花枯萎病菌营养亲和群的初步研究

从新疆各植棉区采集棉花枯萎病病株,经分离纯化获４９个单胞菌株。接种试验表明：４９个菌株均使棉花产生枯萎病症状。利用氯酸钾诱变棉花枯萎病菌,产生抗氯酸盐的硝酸盐营养突变株,４９个菌株共诱发获得３３６个ｎｉｔ突变株,将获得的ｎｉｔ突变株作营养亲和性配对反应,可将４９个菌株分为４个亲和群,其中４６个菌株属同一亲和群,它们均与７号小种的ｎｉｔ突变株相亲和,其余３个菌株分别属于其它亲和群。     

邓小平“三农”思想探析

邓小平同志的农业、农村和农民思想,是其它一切思想的基础.本文从农业是国民经济的基础、农业发展的根本道路、农业的 两个飞跃 、农业发展的根本道路四个方面,对邓小平同志的三农思想进行了探析     

茶叶清洁生产与茶园施肥

阐述了茶叶清洁生产的概念、内涵,分析了我国茶园施肥存在的主要问题及负面影响,探讨了茶叶清洁生产中适宜的肥料投入品的选择及合理的施肥技术。     

固相萃取-气相色谱-质谱法测定水中23种多氯联苯和10种有机氯农药残留

开发了一种采用固相萃取技术同时萃取水样中23种多氯联苯(PCBs),6种滴滴涕(DDT)和4种六六六(HCH),并采用气相色谱-质谱联用仪进行检测的方法。该方法对水样中PCBs、DDT和HCH检测具有较高的灵敏度和较宽的线性范围,最低检测限分别为0.39～4.20 ng/L、0.06～0.15 ng/L、0.52～1.79 ng/L,加标回收率分别为78.1%～109.8%、86.1%～105.5%和81.6%～107.2%。     

我国沿岸海域环境污染对渔业可持续发展的影响及对策探讨

阐述了我国沿岩海域主要污染物的种类，污染物质的迁移、转化引起的水域环境污染及污染现状等，讨论了环境污染对渔业生产的影响，从管理、防治、保护等方面提出了对策，以实现渔业的可持续发展目标。