印楝素A和印楝素B的稳定性比较

印楝种子甲醇抽提物在甲醇+水(体积比为55:5)中于(54±1) ℃下贮存7和14 d,印楝素A的降解率分别为33.59%和54.45%,印楝素B的为11.96%和21.11%;印楝种子甲醇抽提物在(54±1) ℃下贮存7和14 d,印楝素A的降解率为82.35%和94.79%,印楝素B的为20.32%和54.75%;印楝素干粉于(54±1) ℃下贮存14 d,印楝素A和印楝素B的降解率分别为90.15%和81.85%.在(54±1) ℃下热贮7 d,在甲醇、甲醇+水(9:1)和甲醇+印楝油(9:1)中印楝素A的降解率分别为29.65%、44.99%和12.76%,印楝素B的分别为19.68%、25.65%和9.67%.印楝油对印楝素A和印楝素B均有保护作用.     

印楝素A和印楝素B的稳定性比较

印楝种子甲醇抽提物在甲醇 水 (体积比为 55∶5) 中于 (54±1)℃下贮存 7和 14d, 印楝素A的降解率分别为33 59%和 54 45%, 印楝素B的为 11 96%和 21 11%; 印楝种子甲醇抽提物在 (54±1)℃下贮存 7和 14d, 印楝素A的降解率为 82 35%和 94 79%, 印楝素B的为 20 32%和 54 75%; 印楝素干粉于 (54±1)℃下贮存 14d, 印楝素A和印楝素B的降解率分别为 90 15%和 81 85%。在 (54±1)℃下热贮 7d, 在甲醇、甲醇 水 ( 9∶1 ) 和甲醇 印楝油(9∶1) 中印楝素A的降解率分别为 29 65%、44 99%和 12 76%, 印楝素B的分别为 19 68%、25 65%和 9 67%。印楝油对印楝素A和印楝素B均有保护作用。     

印楝果实成熟期调查及不同采收期印楝素含量的变化

印楝果实的成熟期较长,不同成熟期所采样品的百粒重、印楝素含量和印楝素产量也不相同,调查和实验结果显示：印楝果实的成熟期集中在7月初至9月中旬期间;早期样品的百粒重低而印楝索含量高,后期样品百粒重高而印楝素含量低,成熟率约30％时百粒重和印楝素含量基本稳定,印楝素产量在果实成熟后基本稳定;同一时期采摘的样品中,绿色果皮的样品印楝素含量和产量均高于黄色果皮的样品。     

印楝种仁中印楝素含量的变异

通过多组对比试验得出结论:同株印楝的印楝素A、印楝素B含量年际间差异显著,印楝素(A+B)含量差异不显著;嫁接株与母株间印楝素含量差异显著,同一无性系的不同嫁接株间印楝素含量差异不显著;印楝素A含量随储藏时间的延长而降低,印楝素B含量随储藏时间延长而先增加后降低;花期对植株施肥会降低印楝素含量;果实采摘后5~10 d脱洗时,种仁内印楝素含量最高;脱洗后种子日照10~20 d时,印楝素含量最高。     

生物农药印楝素的热稳定性研究

研究了水分、黄曲霉、溶剂、乳化剂、稳定剂等因素对印楝素热稳定性的影响 ,结果表明 :除去水分、黄曲霉后的固体印楝素稳定性有明显改善 ,印楝素在各种溶剂中的稳定性为 :二甲苯 -乙腈 ( 2∶1 )≈二甲苯 -乙酸乙酯 ( 2∶1 ) >二甲亚砜 >乙腈 >乙酸乙酯 >丙酮 >甲醇≈乙醇 ;各种乳化剂的存在加速印楝素的分解 ,其中热分解速度 :十二烷基苯磺酸钠 >吐温 - 80 >CH1 0 0 >吐温 - 2 0≈CH40 0 ;加入热稳定剂后能明显改善印楝素的稳定效果 ,其中环氧化豆油的稳定效果较好     

印楝素A和印楝素B的生物活性及增效作用

印楝素A、印楝素B和印楝素A B(1：1,m／m)对斜纹夜蛾2龄幼虫具有较好的拒食活性,处理后24h,拒食中浓度(antifeedant medial concentration,ARC50)分别为0．97mg／L、2．42mg／L和1．01mg／L~印楝素A与印楝素B按质量比1：1混合后具有增效作用。印楝素A、印楝素B和印楝素A B对大菜粉蝶3龄幼虫具有一定的拒食活性,处理后24h,AFC50分别为176．67mg／L、224．48mg／L和149．99mg／L印楝素A与印楝素B按质量比1．6：1混合后具有一定的增效作用。3mg／L印楝素A和印楝素B能延缓斜纹夜娥的化蛹,降低蛹重,且印楝素B对蛹的影响高于印楝素A。1mg／L印楝素A与印楝素B能明显降低斜纹夜娥幼虫的体重,处理后3～5d,印楝素B对斜纹夜蛾幼虫的体重的影响明显高于印楝素A。     

印楝素B稳定性的观察

室内试验测定结果表明,印楝种子甲醇抽提物中印楝素B在甲醇、乙醇、乙腈和DMF等溶剂中具有良好的稳定性。在54℃下贮存14 d,印楝素B的降解率分别为-1.87%、1.13%、-2.32%和5.24%。印楝素干粉中印楝素B在甲醇、乙醇、丙酮和DMF等溶剂中的稳定性不佳,在54℃下贮存14 d,印楝素B的降解率分别为24.07%、35.65%、19.88%和10.29%。印楝种子甲醇抽提物在甲醇 水(55/3,V/V)中于0℃下贮存7 d和14 d,印楝素B的降解率分别为-2.98%和1.03%。于54℃下贮存7 d和14 d,印楝素B的降解率分别8.73%和15.09%。于甲醇 水(9/1,V/V)中在54℃下热贮14 d,印楝素B的降解率为52.47%,稳定性高于印楝素A。紫外光下照射19 d,印楝种子甲醇抽提物中印楝素B的降解率为-2.94%。     

印楝素的稳定性研究

文中对影响印楝素稳定性的因素做了较系统地研究,诸如温度、溶剂极性、酸碱度、抗氧剂和抗光剂等.结果表明,在室温下,印楝素在pH4~6的溶液中比较稳定,而在强酸、碱、水溶液以及热甲醇溶液中分解较快.环氧化豆油有抑制印楝素热分解的作用,对氨基苯甲酸有抑制印楝素光分解作用.     

干热河谷纯林和混交林下印楝养分特征

为了更好地指导干热河谷不同恢复模式下人工林经营过程中的养分管理以及造林树种和造林模式的筛选,以元谋干热河谷印楝(Azadirachta indica)纯林及印楝×大叶相思(Acacia auriculiformis)混交林为研究对象,对林地土壤、印楝各器官5种主要元素(N、P、K、Ca、Mg)养分质量分数进行了对比研究。结果表明:印楝混交林内土壤全N、全P、全K及其速效养分质量分数均显著高于纯林(P<0.05);纯林和混交林内印楝各器官5种养分元素总量大小顺序发生了改变,纯林内为叶>枝>皮>根>干,混交林内为叶>皮>根>枝>干;纯林内印楝各器官(除干外)N、P质量分数均低于混交林,且叶内N/P比(8.0)较混交林(11.1)小,显示对N素的缺乏;元谋干热河谷印楝养分富集系数较高,印楝可能通过奢侈吸收提高植物体内养分含量来适应干热河谷土壤贫瘠环境。     

水分对印楝素稳定性的影响

报道了水分对印楝素稳定性的影响.印楝甲醇抽提物和印楝素纯品试验表明:水分是促进印楝素降解的一个重要因素.当水与甲醇组成的混合溶剂中水的体积分数为1 8%、3 5%、5 2%、6 8%、8 3%时,在(54±1)℃保存14d后,印楝甲醇抽提物中的印楝素分别降解40 4%、45 4%、47 3%、50 1%、56 2%,大多高于对照(甲醇溶液)分解率(42 1%);印楝素纯品分别降解43 3%、47 2%、53 4%、51 9%、59 5%,都高于对照(甲醇溶液)分解率(42 0%).在(0±1)℃保存14d后这4种溶剂中的印楝素都基本不降解,在室温下保存14d后都只有少量降解.纯水中的印楝素在(54±1)℃下最多保存7d即全部降解.     

外源鲨烯和茉莉酸甲酯对印楝素生物合成代谢网络的影响

基于广泛靶向代谢组技术,以印楝愈伤组织为材料,研究了外源鲨烯和茉莉酸甲酯(MeJ)处理对印楝素生物合成代谢网络的影响.通过饲喂印楝愈伤组织鲨烯和茉莉酸甲酯,结合超高效液相色谱和质谱分析手段,对饲喂处理后的印楝愈伤组织代谢物进行定性定量分析.结果 表明,MeJ和鲨烯显著影响印楝愈伤组织的代谢活动,MeJ处理后共检132种差异代谢物,包括52种初生代谢物和80种次生代谢物.MeJ调控有机酸、脂质、氨基酸以及黄酮类和酚类物质的代谢,抑制印楝素B、诺米林和葫芦素E的合成.鲨烯处理检出137种差异代谢物,32种代谢物表达上调.MeJ和鲨烯均显著促进印楝素A、Azadiradione、Nimbin和Salannin的合成,抑制印楝素B和D的合成.初步阐明了MeJ和鲨烯影响印楝素A合成的机制,即二者通过调控初级代谢途径,影响印楝素合成前体的供给;通过抑制固醇类物质的次生代谢,促使更多的前体进入印楝索A合成的代谢流,进而调控印楝素的生物合成.     

植物源农药印楝素的研究与应用 (特约综述)

印楝素是目前世界上最优秀的植物源农药,田间登记应用已30多年,对全球作物保护和生态安全发挥了重要的作用.本文回顾了印楝素的发现和印楝在中国引种情况,总结了印楝素结构鉴定与全合成的历程,重点介绍印楝素拒食、抑制昆虫生长发育、诱导细胞凋亡和自噬的分子作用机理以及印楝分子生物学、印楝素生物合成研究的最新进展.1983年,赵善欢等成功地将印楝引种中国,随后我国许多学者开展印楝引种与繁育,种植面积曾超过6万hm2,为我国印楝素杀虫剂的规模化生产提供了原料保障.1997年印楝素以新化合物结构作为新农药在我国登记,实现了商业化应用,2014年成为农业部推荐使用的低毒低残留农药主要品种,获得了显著的经济和生态效益.我国学者发现了印楝素诱导细胞自噬现象,阐明了印楝素诱导细胞凋亡和自噬的分子调控机理.随着强化农产品质量安全的源头控制,印楝素的研究和应用将会越来越深入普及.今后要进一步加强基础研究,明确印楝素的分子靶标,为印楝素的科学使用提供理论基础.     

3种常用植物源农药对甘蓝蚜的室内毒力测定和田间防效试验

为评估植物源农药对甘蓝蚜的毒力和防效,科学指导蔬菜用药,选取3种常用植物源农药,进行室内毒力测定和田间防效试验。毒力测定结果：10%印楝素ME对甘蓝蚜毒力作用最强,LC₅₀依次为1.5%除虫菊素EW 0.100 2 mg/L>5%阿维菌素EC 0.059 7 mg/L>10%印楝素ME 0.031 7 mg/L。防效试验结果：10%印楝素ME 2 000倍液在药后3 d达到最高,校正防效为91.15%; 5%阿维菌素EC 2 000倍液在药后3 d达到最高,校正防效为90.20%;1.5%除虫菊素EW 1 500倍液在药后7 d达到最高,校正防效为84.18%。结论：3种植物源农药都表现出一定的毒力强度和很好的防治效果,可参考选用。     

油菜区域试验产量性状及其稳定性分析

利用2008与2009年两年的浙江省油菜区域试验资料,采用作物品种区域试验非平衡资料的统计分析方法,分析了品种产量及其构成因素的方差分量,同时对参试品种进行稳定性分析。结果表明：‘037-77’品种产量较高,但与对照品种‘浙双72’没有显著差异;试点和年份×试点的互作效应对产量及其构成因素影响较大;除‘浙杂0603’和‘黔杂2630’对环境指数反应较敏感及‘J6’和‘ZY-10’一致性较差外,其余品种均表现出相似的稳定性。     

水分胁迫对苹果不同品种光合特性的影响

研究了苹果7个品种一年生嫁接苗叶片净光合速率(Pn)、蒸腾速率(Tr)、水分利用率(WUE)、气孔导度(GS)等指标对土壤水分胁迫的响应。土壤干旱胁迫时苹果上述生理过程均受到显著影响,但各项生理指标对水分胁迫的敏感性不同。随着水分胁迫加剧,净光合速率、蒸腾速率、气孔导度均表现为下降的趋势,而水分利用率先升高后降低。不同品种的光合和蒸腾性能指标对水分胁迫的响应不同,抗旱性强的品种在胁迫条件下净光合速率、蒸腾速率、气孔导度均较低,且下降的幅度大;抗旱性强的品种在中度胁迫条件下水分利用率高,且升高的幅度大。     

小麦品种审定中品种的合理评价问题

 以山东和江苏的小麦区试为例，探讨了品种审定中如何公正合理评价品种的问题。⑴品种区试的精确度标准：建议采用CV≤D（n/2）#+（1/2）/t#-α来估计。⑵联合方差分析的统计模型问题：认为年份和试点转换为环境因素的联合方差分析是较好的模型。⑶适应性和稳定性分析：提出b#-i为适应性参数，a#-i为稳定性参数。⑷合理评价品种：推荐采用参数分组估计法。     

Determination of Amylose Content and Its Relationship with RVA Profile Within Genetically Similar Cultivars of Rice(Oryza sativa L.ssp.japonica)

Anther culture pure lines with antisense Wx gene were generated by Agrobacterium tumefaciens-mediated co-transformation followed by anther culture in transgenic rice(Oryza sativa L.ssp.japonica).The antisense Wx transgenic pure lines were used to analyze the differences and the relationship between RVA eigenvalues among the lines with different amylose contents.77 pure lines of anther culture having antisense Wx gene were studied for the amylose content of its offspring cultivar,Wuyunjing 7.It was found that levels of amylose content were similar to the control in 19 lines(16.0%);1-5% lower than control in 50 lines,of which,within 11.0-13.9% in 40 lines;and 3.1-4.0% in 8 lines.The effect of the amylose content on RVA eigenvalue was analyzed through the RVA profile graphic comparison and test of significance for RVA eigenvalues.The analysis of RVA profiles with different amylose contents indicated that there were two kinds of RVA profiles within genetically similar cultivars.The lines with 3.1-4.0% of amylose content were distinctly different from other lines and conventional glutinous rice.The comparison of the similarity curve of RVA profile of the lines with different amylose contents showed that the lines with lower amylose content had a distinguished RVA profile with the curve increasing gradually,but not exceeding the first apex.The test of significance for eigenvalues of the RVA profile in the lines with different amylose contents indicated that there were five eigenvalues remarkably different among the lines with 3.1-4.0% of amylose content compared with other two groups.Further,there were three eigenvalues remarkably different among the lines with 11.0-13.5% of amylose content compared with control group.An optimized mathematical model,which characterizes the relationships between the amylose content and RVA eigenvalue,has been established in this study.From this model,it was clearly indicated that the parameters PeT and SBV were more related to amylose content.It was concluded that the differences in amylose content not only affected the eigenvalues of RVA but also caused different RVA profiles within genetically similar cultivars.The introduction of antisense Wx gene could lead to reduce the amylose content and lay theoretical foundation for quality improvement in rice breeding programs.     

Determination of Amylose Content and Its Relationship with RVA Profile Within Genetically Similar Cultivars of Rice (Oryza sativa L.ssp.japonica)

Anther culture pure lines with antisense Wx gene were generated by Agrobacterium tumefaciens-mediated co-transformation followed by anther culture in transgenic rice (Oryza sativa L.ssp.japonica).The antisense Wx transgenic pure lines were used to analyze the differences and the relationship between RVA eigenvalues among the lines with different amylose contents.77 pure lines of anther culture having antisense Wx gene were studied for the amylose content of its offspring cultivar,Wuyunjing 7.It was found that levels of amylose content were similar to the control in 19 lines (16.0%);1-5%lower than control in 50 lines,of which,within 11.0-13.9% in 40 lines;and 3.1-4.0% in 8 lines.The effect of the amylose content on RVA eigenvalue was analyzed through the RVA profile graphic comparison and test of significance for RVA eigenvalues.The analysis of RVA profiles with different amylose contents indicated that there were two kinds of RVA profiles within genetically similar cultivars.The lines with 3.1-4.0% of amylose content were distinctly different from other lines and conventional glutinous rice.The comparison of the similarity curve of RVA profile of the lines with different amylose contents showed that the lines with lower amylose content had a distinguished RVA profile with the curve increasing gradually,but not exceeding the first apex.The test of significance for eigenvalues of the RVA profile in the lines with different amylose contents indicated that there were five eigenvalues remarkably different among the lines with 3.1-4.0% of amylose content compared with other two groups.Further,there were three eigenvalues remarkably different among the lines with 11.0-13.5% of amylose content compared with control group.An optimized mathematical model,which characterizes the relationships between the amylose content and RVA eigenvalue,has been established in this study.From this model,it was clearly indicated that the parameters PeT and SBV were more related to amylose content.It was concluded that the differences in amylose content not only affected the eigenvalues of RVA but also caused different RVA profiles within genetically similar cultivars.The introduction of antisense Wx gene could lead to reduce the amylose content and lay theoretical foundation for quality improvement in rice breeding programs.