用于农产品保鲜的有机物水溶液相变蓄冷剂

研制了一种有较高相变潜热、低Onset温度,适用于农产品贮运保鲜的高效安全有机物水溶液相变蓄冷剂。从初选的甘氨酸、赖氨酸、山梨醇、脯氨酸、葡萄糖等5种有机物中,利用DSC法筛选了相变潜热较高的甘氨酸水溶液为主储能剂,再与0.1 mol/L的丙三醇进行复配获得更低的Onset温度。以质量分数为0.1%的苯甲酸钠作为防腐剂延长蓄冷剂的使用期限,并用高吸水性树脂作为基质,得到蓄冷剂的最终配方为:甘氨酸0.4~0.8 mol/L,丙三醇0.1 mol/L,苯甲酸钠质量分数为0.1%,其余为水,并添加质量分数为0.75%~0.81%的SAP作为基质。通过调节甘氨酸浓度,可获得相变潜热为296.4~305.9 J/g,Onset温度为-7.3~-5℃的系列有机物水溶液相变蓄冷剂,并且无明显过冷度和相分离现象,安全性好,具有应用前景。     

两品种茶园茶蚜和假眼小绿叶蝉天敌优势种的比较

为了科学施药,合理保护和利用天敌进行茶园害虫的综合防治,开展乌牛早和白毫早茶园主要害虫茶蚜和假眼小绿叶蝉的优势种天敌评定和比较。对两品种茶园间害虫及其天敌的数量进行t检验。结果表明,两品种茶园之间春夏季2种害虫和8种天敌差异均不显著,秋冬季草间小黑蛛(3.7160)和茶色新圆蛛(4.3144)差异极显著;乌牛早茶园春夏季与秋冬季之间八点球腹蛛(2.6298)差异显著,白毫早茶园茶色新圆蛛(4.0056)差异极显著,草间小黑蛛(2.8160)和粽管巢蛛(2.1408)差异显著,其余差异均不显著。采用灰色关联度分析方法和生态位分析方法对两品种茶园2种害虫与其天敌在数量、时间和空间等方面关系进行分析,综合评判出天敌优势种,并进行比较。结果表明,春夏季两品种茶园茶蚜前3位优势种天敌均是锥腹肖蛸、三突花蟹蛛和粽管巢蛛,但位次不同;假眼小绿叶蝉前1、2位天敌均是粽管巢蛛和锥腹肖蛸,但第3位天敌不同。秋冬季两品种茶园茶蚜前3位的天敌中均有鳞纹肖蛸和八点球腹蛛,假眼小绿叶蝉前3位天敌中均有草间小黑蛛和粽管巢蛛。春夏季和秋冬季比较,茶蚜前3位天敌乌牛早茶园中只有三突花蟹蛛相同,白毫早茶园只有锥腹肖蛸相同;假眼小绿叶蝉前3位天敌中,乌牛早茶园只有粽管巢蛛相同,而白毫早茶园有锥腹肖蛸和粽管巢蛛2种天敌相同。春夏季茶树品种对茶蚜天敌优势种影响大。茶树品种不同,茶园的生物物理和生物化学条件也不完全相同,从而影响茶树害虫及其天敌的种群动态差异,造成害虫优势种天敌的差异。     

家庭农场对农地经营权抵押贷款的需求及影响因素研究——以江苏省南京市高淳区及其周边地区为例

着眼于江苏省南京市试点区(高淳区)与非试点区,从家庭农场基本情况、家庭农场主贷款意愿及其影响因素3方面进行,通过问卷调查、访谈、实地考察等方式,结合Logistic模型分析进行实证检验,探讨家庭农场对农地经营权抵押贷款的意愿需求及其影响因素。结果表明,受教育程度、家庭农场的年毛收入水平、家庭农场的耕地面积、贷款利率、贷款期限以及其他贷款满足程度对于家庭农场农地经营权抵押贷款的意愿需求有着显著的影响。提出了相应的政策建议:政府要加大对农地经营权抵押贷款政策的宣传和普及力度,银行、农村合作社等金融机构要结合现阶段家庭农场的实际需求调整农地经营权贷款的利率和期限,同时要增加家庭农场主教育年限以及鼓励更多知识分子进入家庭农场的经营管理。     

Spatio-temporal pattern evolution and spatial spillover effect of green development efficiency: Evidence from Shandong Province,China

Improving green development efficiency is urgently required, yet challenging, since it comprehensively reflects the bidirectional evolutionary relationship between regional development and resource and environmental consumption. The issue of regional green development efficiency has become a key topic; however, where the increase in efficiency originates and its spatial spillover effect remains unclear to date. Therefore, the spatial spillover effect of the green development efficiency of Shandong Province was quantified through the slack variable (SBM)-Undesirable and Spatial Durbin model. The green development efficiency showed clear spatial differentiation in Shandong Province. This was more obvious than the polarized development trend of the provincial capital circle that has Jinan at its core and the eastern coastal region with Qingdao at its core. Green development efficiency has a significant spatial spillover effect. The regression coefficient of the direct effect of the economic development level is positive. The regression coefficient of the indirect effect of the marketization level and government financial support level is negative. Science and technology played a positive role in the promotion of the green development efficiency of local and neighboring cities. This study contributes empirical evidence to the green development efficiency associated with regional development and resource and environment consumption of Shandong Province.     

Mapping of quantitative trait loci conferring resistance to bacterial wilt in tobacco (Nicotiana tabacum L.)

Tobacco bacterial wilt (TBW) is one of the most serious tobacco diseases in the world. Studies have shown that tobacco resistance to TBW is quantitatively inherited. This study aimed to map quantitative trait loci (QTL) conferring TBW resistance. An F_2 : 3 population containing 237 lines was developed from a cross between two flue‐cured tobacco cultivars, ‘Yanyan 97’ (YY97; moderately resistant to TBW) and ‘Honghua Dajinyuan’ (HD; highly susceptible to TBW), and a linkage map consisting of 201 simple sequence repeats (SSR) markers and spanning a total length of 2326.7 cM was constructed based on the population. Field experiments were conducted 2011 and 2012, and disease symptoms were investigated three times in each year. The phenotypic data were analysed either separately or jointly for QTL mapping using the software QTLNetwork 2.1. Eight QTL with significant main effects were mapped on chromosomes 2, 6, 12, 17 and 24. A major QTL (qBWR17a) was detected on chromosome 17, which explained up to 30% of the phenotypic variation. The results can facilitate marker‐assisted selection (MAS) in TBW resistance breeding programme.     

分子标记辅助选择改良杂交水稻的白叶枯病抗性

分子标记辅助选择技术以其对目标基因快速而精确的选择为回交育种提供了非常有效的工具。华中农业大学作物遗传改良实验室运用分子标记辅助的回交育种方法,将广谱高抗白叶枯病基因Ｚａ２１迅速导入到杂交水稻的两个优良恢复系明灰６３和６０７８之中,成功地完成了其抗生改良,并通过配组而达到了改良杂交水稻抗性的目的。本研究所运用的分子标记辅助的水稻回交育种程序是：通过一次杂交、二次回交改良杂交水稻抗性的目的。本研究所     

番茄、黄瓜的魔芋多糖涂膜保鲜研究

以魔芋精粉、虫胶、乳球菌肽等作为涂膜保鲜原料,对番茄、黄瓜保鲜的适宜浓度及其最佳配比进行研究.结果表明,浓度为0.5 %的复合涂膜液(魔芋精粉、虫胶、乳球菌肽三者复合)对番茄保鲜效果最好,浓度为0.3 %的复合涂膜液对黄瓜保鲜效果最好;在贮藏过程中,总酸度、总糖度、维生素C等与新鲜的番茄、黄瓜接近.利用魔芋多糖进行番茄、黄瓜涂膜保鲜是一种有效的贮藏保鲜方法.     

森林可持续发展的动态优化模型

运用动态规划方法讨论森林可持续发展问题，建立了森林自然发展模型和森林可持续发展的优化开发模型，给出了相应的迭代公式，并选用青冈－夏蜡梅群落进行模拟计算。结果表明经过一段时间的自然发展，森林群落可达到稳定态，夏蜡梅群落必将过渡到青冈－夏蜡梅稳定群落。其后，各阶段各树种的数量有微小变化，但总体稳定，且算法快速收敛于稳定点。图3表2参4。     

绿僵菌不同菌株DNA多态性的RAPD分析

采用RAPD－PCR技术分析了4个绿僵菌株的DNA遗传多态性。从160条引物中筛选出27条引物，对各菌株进行PCR扩增，结果4个绿僵菌菌株共扩增出334个位点，其中多态性位点299个，占89．5％，表明各菌株间具有较丰富的遗传多态性。菌株DNA多态性与原寄主和孢子形态表现出明显的相关性，但与对松墨天牛幼虫的毒力间未表现出相关性。图2表4参7     

黑龙江省农田土壤蓄水量盈亏状况的垂直变化规律研究

以农田土壤水分实测资料为基础 ,依据农田土壤水分常数与作物生长发育的关系创建了土壤蓄水量盈亏值指标。选择 3个典型站点研究黑龙江省农田土壤水分盈亏状况的垂直变化规律 ,结果为 :海伦从表层到 5 0 cm各个土层均为盈余 ,而且随深度的增加盈余先增加后下降 ,2 0 cm处为最高值 ;泰来的土壤水分从表层到 30 cm为增加 ,之后又下降 ,而且以 2 0 cm为界将盈余区与亏缺区划分开 ;总平均来看 ,宝清土壤水分随深度呈减少趋势 ,盈余减小 ,亏缺增大