中国烤烟种植区域布局变迁及其影响因素

从"两大烟区"(南、北烟区)和"五大烟区"(西南烟区、东南烟区、长江中上游烟区、黄淮烟区、北方烟区)2个层面,对1983—2012年中国烤烟种植区域布局变迁进行描述性统计分析。结果表明,1983—2012年,中国烤烟种植呈现"北烟南移"格局,尤其是向西南地区迁移的趋势明显。在此基础上,根据农业区位理论与生产者行为理论,进行变量选取、理论假设和模型构建,并利用Eviews软件对影响烤烟主产区区域格局变迁的因素进行计量分析。结果表明,烤烟主产区区域格局的变迁受到土地资源、地理气候、经济、技术进步和国家政策等因素的共同影响。对于黄淮主产区而言,影响最显著的因素是人均耕地、农户粮食供给水平、技术进步、国家政策和农民非农就业机会;对于西南主产区而言,影响最显著的因素是农户粮食供给水平、技术进步、国家政策和自然灾害状况。     

11种野生苹果种质资源RAPD标记研究

利用Ｃ．Ｇ．Ａｌｐｈａ等的ＤＮＡ微量提取法,提取了山荆子ＭａｌｕｓｂａｃｃａｔａＢｏｒｋｈ．等１１个苹果属植物野生种类的ＤＮＡ,并用５对引物对所研究材料的ＲＡＰＤ标记进行了研究。探讨了叶片中富含多酚类化合物的苹果植物叶片ＤＮＡ的提取及纯化方法,并初步建立了野生苹果ＲＡＰＤ标记的ＰＣＲ反应条件。     

DNA methylation status in tissues of sheep clones

Genomic imprinting and DNA methylation play an important role in mammalian development. Many cloned animals showed heterogeneous DNA methylation profiles. However, there are fewer reports in cloned lambs because of a lack of genomic imprinting information. In this study, we investigated DNA methylation patterns in CpG islands and differentially methylated regions of putative imprinted gene Peg10 and imprinted genes Dlk1, Igf2R and H19 in cloned lambs. Five organs from two cloned lambs died shortly after birth and two normal controls were investigated. We observed normal DNA methylation profiles in cloned lambs. The imprinted genes Dlk1, Igf2R and H19 in livers, kidneys, hearts, muscles and lungs of the two cloned lambs exhibited relatively normal DNA methylation, except for Peg10 showing some differences between controls and cloned lambs. Our results indicate that somatic cell nuclear transfer-produced sheep exhibited relatively normal DNA methylation pattern and experienced normal DNA methylation reprogramming at imprinted loci.     

蔷薇科甜茶加工应用研究进展

蔷薇科甜茶营养丰富,含有甜茶甙、多酚、黄酮等多种活性物质。总结了蔷薇科甜茶的加工应用状况,为蔷薇科甜茶的进一步加工应用和市场开发提供参考。     

饲料用玉米加工中的HACCP体系的建立与应用

饲料的安全性直接影响到动物产品的质量安全。依据国际先进的HACCP质量管理体系,对饲料用玉米加工过程中主要危害因素进行分析,确定出原料接收、原料贮藏、原料清理、原料研磨、添加剂、包装环节为关键控制点(CCP),并提出相应的控制措施,可以有效控制饲料用玉米安全性和产品质量,减少产品的安全风险,为饲料用玉米质量安全控制提供借鉴。     

Comparative studies on survival and growth performance among diploid,triploid and tetraploid dojo loach <Emphasis Type="Italic">Misgurnus anguillicaudatus</Emphasis>

To determine the cytotype with better traits for the aquaculture practices of the dojo loach Misgurnus anguillicaudatus from the viewpoint of fish farming improvement, factorial crosses (2n♀ × 2n♂, 2n♀ × 4n♂, 4n♀ × 2n♂, 4n♀ × 4n♂) were conducted between natural diploids (D) and tetraploids (T), producing DD, DT, TD, and TT groups (female listed first). The potential benefits of the different cytotypes in culture were evaluated by comparing growth performance and survival rate for a 15-month rearing trial under the same production conditions. The average fertilization rate in DT and TT was significantly lower than in the DD and TD groups, possibly indicating the poor fertilizing capacity of the tetraploid sires. Survival rate in DT and TD was slightly lower than in DD but significantly higher than in the TT groups. Tetraploid females produced obviously larger eggs than diploids and, subsequently, significantly longer initial body length of TT and TD than DD and DT fry. However, from the second month of the growth trial, TT suffered higher mortality than other cytotypes, which significantly influenced morphometric growth parameters. The TD group exhibited superior growth performance throughout the experiment. The mean body length of DT was comparable with that of DD fish during the first 7 months but began to outgrow DD from the 9th month. This study suggests that the relatively better growth of tetraploid and higher survival rate of diploid can be integrated via inter-ploidy hybridization to get TD triploids with better culture traits.     

农抗SH—62产生菌原生质体再生菌株的筛选和再生菌株R-4发酵规律的初步研究

本文报道了农抗SH—62产生菌原生质体再生菌株的筛选和再生菌株R—4的发酵规律。试验表明,通过摇瓶的初筛和复筛,从活性比出发菌株要强的202株再生菌株中,找出R—4、R—66和R—72三株活性最强而又稳定的再生菌株。在再生菌株R—4的发酵试验中,选出了该菌株的最佳发酵培养基为1号培养基,并证明这个菌株对溶氧量并不敏感,在偏碱条件下有利于生长和产素,发酵周期为72小时等最适发酵条件。     

山西省大豆育种现状与发展对策

对山西省近年来审(认)定的大豆品种从产量水平,内在品质等方面进行了简要分析,并与同期审(认)定的国审大豆品种相比较,据此得出山西省大豆育种所取得的成绩和不足,并提出了发展对策.     

空间条件对棉花种子后代植株同工酶影响的研究初报

用聚丙烯酰胺凝胶电泳方法,对经卫星搭载、在外层空间飞行8天的棉花种子第一代和第二代植株的子叶、叶片和花药,进行了酯酶、过氧化物酶和淀粉酶三种同工酶的酶谱分析,发现某些后代植株的酯酶同工酶和过氧化物酶同工酶与对照相比在活性和酶带数目上都有变化,但没有观察到淀粉酶同工酶在处理和对照之间的差异。     

果蔬通风预冷技术研究进展

预冷是现代果蔬流通体系的重要内容，也是冷链流通的首要环节。它可以迅速排除果蔬采后的田间热，降低呼吸作用，延缓其成熟衰老的速度，提高贮藏寿命。通风预冷因其适应性广、投资和运转费用少，易于在生产上推广应用，是较为实用、有效的预冷方法。介绍了预冷保鲜的作用和方法，综述了通风预冷技术的研究与发展状况，提出了发展预冷环节需要考虑和解决的问题。