森林资源二类调查中小班区划方法研究

通过对森林资源二类调查中小班区划方法进行改进得到连续小班区划方法 ,试验证明这种方法可以节省大量野外调查时间 ,大幅度提高小班界线区划的准确性 ,使小班界线相对稳定 ,调查成果可提供落实到山头地块的森林资源现状和动态变化数据及图面材料     

国内外水土流失与土壤退化现状及特点分析

土壤侵蚀是土地退化的主要原因,全球约有1 965.0万km2的面积受到各种形式土壤退化的影响,水土流失与土地退化给人类的可持续发展带来了巨大的压力。我国水土流失尤为严重,根据最新第2次水土流失遥感调查结果表明,全国现有的水土流失面积为356.0万km2。轻度水蚀区主要分布在东中部,中度水蚀区绝大部分在中西部,强度及以上的水蚀区主要在西部地区。严重的水土流失使生态环境不断恶化,加剧土地资源危机,已成为严重的社会问题。     

Comparison of Conventional Washing Processing and pH Shift Processing on Gelation Characteristics of Bighead Carp (Aristichthys nobilis) Muscle Proteins

In this study, gelation characteristics of bighead carp (Aristichthys nobilis) protein isolates prepared by pH shift processing were investigated as compared with those of surimi prepared by conventional wash processing. Results showed that the gel from alkali-aided protein isolate exhibited a higher breaking force than that from conventional washed surimi (p < 0.05). However, the gel from conventional washed surimi had higher whiteness (p < 0.05) and lower expressible moisture (p < 0.05). The rheological study showed that protein isolates exhibited different storage modulus and loss tangent patterns from conventional washed surimi during heating. Acid-aided processing could lead to higher denaturation and dissociation for fish muscle myosin and a coarser gel network from the sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) pattern and the scanning electron microscopy (SEM). Overall, there is a potential to apply pH shift processing, especially alkali-aided processing, to extract more proteins from bighead carp muscle for the production of surimi-based food.     

创新驱动背景下的国际科技合作模型兼论中奥科技合作模式

广泛开展国际科技合作是当前全球各国提升创新能力、弥补自身短板、实现高质量发展的内在需求。通过梳理2015—2019年全球创新发展报告,总结全球科技创新格局,得到创新规律演变趋势:从重视基础研究拓展到重视科技创新绩效;从创新数量向创新质量转变;全球创新呈多极化发展趋势;科学与技术一体化;创新链与产业链融合;通过国际合作推动科技创新。在此背景下,借鉴巴斯德象限模型,结合中国科技创新实际,提出了创新链与产业链双向融合的国际合作路径,并以中奥科技合作为例提出相应的对策建议。     

Effects of different dietary copper sources on the growth and intestinal microbial communities of Pacific white shrimp (Litopenaeus vannamei)

An 8‐week feeding trial was conducted to evaluate the effects of dietary copper sources on growth performance and intestinal microbial communities of juvenile Pacific white shrimp (Litopenaeus vannamei). Four isonitrogenous (420 g/kg crude protein) and isolipidic (70 g/kg crude lipid) experimental diets were formulated to contain different copper sources, Diet NSC (no‐supplemented copper), Diet CS (copper sulphate), Diet Availa (copper amino acid complex from Availa^®Cu100) and Diet M (1:1, copper sulphate + copper amino acid complex). A total of 360 Pacific white shrimp juveniles (initial weight: 1.86 ± 0.03 g) were randomly allocated into four groups, with three replicates per group and 30 shrimps each replicate. An Illumina‐based sequencing method was used to analyse the intestinal bacterial composition of shrimp juveniles. The results revealed that shrimps fed Diet M had significantly higher percent weight gain (PWG) than that fed Diet NSC and Diet CS, while there were no significant differences between Diet M and Diet Availa. Survival was not affected by the dietary copper sources. Proteobacteria and Bacteroidetes were dominant in the intestines of Pacific white shrimp. Shrimps fed Diet M and Diet Availa had higher bacterial richness and diversity than those fed Diet NSC and Diet CS with no significant differences among all treatments. Furthermore, Diet M and Diet Availa which contained copper amino acid complex reduced the relative abundance of Vibrionaceae in shrimp intestinal tract. This study indicated that dietary copper sources could affect the intestinal microbial communities and diets supplemented with Availa^®Cu100 could have a positive impact on the growth performance and decrease the potential risk of disease in Pacific white shrimp.     

湖南省生姜资源主要农艺性状鉴定评价

研究旨在对湖南省47份生姜种质资源的15个数量性状和10个质量性状进行分析,以期探索湖南省各地生姜资源间的亲缘关系及变异特性,为湖南省生姜种质评价与新品种创制提供理论依据。用Excel及SPSS等对调查收集的农艺性状进行分析,结果表明,湖南省生姜资源具有丰富的遗传多样性,变异系数范围为13.22%~40.13%;聚类分析中,47份生姜资源分为2类4个亚组,其中第I类群的41份资源为密苗型资源,第II类群的6份资源为疏苗型资源,亚组I和亚组IV近似纺锤状;亚组II和亚组III近似灯泡状;主成分分析中,提取出的3个主成分累计贡献率达83.078%,分别命名为高产型形态因子、低产型形态因子和产量的叶部因子;相关性分析中,根状茎、株形、地上茎、子姜、叶部等形态因子与根状茎质量呈极显著正相关,分枝数和主茎叶数与根状茎质量呈极显著负相关,表明植株高大,分枝少,地上茎粗壮,根状茎、子姜粗长的品种单株根状茎质量相对更高;通径分析中,主茎叶数、分枝数对根状茎质量的直接通径系数为负,而根状茎、地上茎粗、子姜长、株高等对根状茎质量的直接通径系数为正,表明在一定范围内,生姜植株高大、地上茎秆粗壮、分枝少、叶片较少,根状茎粗长、子姜长的生姜品种具有高产潜力。该试验解析了湖南省生姜资源各主要农艺性状对根状茎质量形成的贡献大小,为更好地指导湖南省生姜生产提供了理论依据。     

湖北省林业有害生物防治工作存在的问题及对策

介绍了当前我省林业有害生物防治的现状,并指出了其面临的主要问题,提出了相应的对策,以期促进林业有害生物防治工作的有效开展。     

利用分子标记辅助选择改良春恢350稻瘟病抗性

水稻抗稻瘟病基因Pigm(t)抗谱广、抗性强。春恢350是超级早稻春光1号的恢复系,该恢复系配合力强,丰产性好,但不抗稻瘟病。本研究以携带抗稻瘟病基因Pigm的谷梅4号为抗源,以春恢350为轮回受体亲本,在回交选育过程中,通过表形筛选与分子标记辅助选择相结合,将Pigm(t)基因导入到春恢350中,获得3个带有目标基因的改良恢复系纯合株系。以江西近年来具有代表性的20个菌株对这3份材料进行抗性鉴定,其抗性频率为85%~100%,而原始对照春恢350的抗性频率仅为5%,表明抗性基因已成功导入春恢350中并表达;并用不育系江农早4号A与改良的春恢350测配,其杂种一代田间表现优势强,抗性强。