Incidence of cabbage maggot (Diptera: Anthomyiidae) infestation and plant damage in seeded Brassica fields in California's central coast

The temporal incidence of cabbage maggot, Delia radicum L. was investigated using three exclusion cage experiments, one each during spring, summer and fall, in broccoli fields as well as two surveys, one each in three broccoli fields, and sixteen turnip plantings in central coast of California. In the cage experiments, sets of broccoli plants were exposed to natural populations of D. radicum flies for ∼14-d periods after plant emergence throughout the growing season. For the surveys, soil, root samples, and yellow sticky traps were collected every week from broccoli fields to determine number of eggs, maggots, feeding-injury and adults. Only roots were sampled from turnip plantings to determine feeding-injury. In all three cage experiments, feeding injury from D. radicum maggot was less during the first 14-d than ∼15–28 d after plant emergence (DAE). In the summer and fall, feeding injury by D. radicum was less during 29–42 and 43–56 DAE than it was 15–28 DAE. In the survey of broccoli fields, a greater number of D. radicum eggs were detected starting the fourth week after planting (WAP). Similarly, an increase in number of D. radicum maggots and feeding injury was observed at fifth and sixth WAP, respectively. However, adults were abundant throughout the growing period. In the turnip survey, increase in injury from D. radicum feeding did not appear until the fifth WAP. Overall, these studies indicate that increased incidence of D. radicum was delayed by about two to three weeks after plant emergence. The implications of these results for timing of insecticide application for D. radicum in the central coast of California are discussed.     

三种黄酮类植物雌激素对樱桃谷鸭钙磷代谢的影响

选用健康的1日龄樱桃谷鸭128只,随机分为4组,分别添加基础日粮、基础日粮+葛根异黄酮组 (10 mg／kg)、基础日粮+葛根素组(10 mg／kg)和基础日粮+大豆异黄酮组(10 mg／kg),分别于21日龄和42日龄屠宰对血清及骨骼里的钙磷及相关指标进行检测．结果发现前期大豆异黄酮的作用效果>葛根异黄酮>葛根素,后期葛根异黄酮的作用效果>大豆异黄酮>葛根素,能增加血清碱性磷酸酶的含量、降低抗酒石酸酸性磷酸酶的含量,同时增加骨骼湿重、长度和钙的含量,说明不同时期的葛根异黄酮和大豆异黄酮可以促进骨的形成、抑制骨的吸收,从而维持骨的健康,且作用效果大小因生长阶段不同而异．     

大豆异黄酮对樱桃谷鸭脂质代谢的影响

将1日龄樱桃谷鸭160只随机分为4个处理组,每组8个重复,每个重复5只,公母各半．1组饲喂基础日粮, 2、3、4组饲喂基础日粮+5、10、15 mg／kg大豆异黄酮,试验期42 d．结果表明:与对照组相比,母鸭添加组中10 mg／kg剂量组的屠宰率升高(P>0．05),皮脂率、腹脂率分别降低17．62％、45％(P<0．05);15 mg／kg剂量组腿肌率和瘦肉率分别升高15．72％、11．04％(P<0．05),皮脂率降低8．05％(P<0．05);公鸭添加组中5 mg／kg剂量组腹脂率比对照组提高了165％(P<0．05)．母鸭添加组血清TG、TC、LDL-C、HDL-C的含量和LPL活力均无显著变化(P>0．05);公鸭添加组5 mg／kg剂量组的LDL-C比对照组提高了4．39％(P<0．05)．     

大豆异黄酮对樱桃谷鸭钙磷代谢的影响

选用健康的1日龄樱桃谷鸭128只,随机分为4组,每组8只(公母各半),在日粮中分别添加0、5、10、15mg/kg大豆异黄酮,于21日龄和42日龄对血清及骨骼里的钙、磷及相关指标进行了检测.结果表明:1~3周龄的樱桃谷鸭血清钙、磷含量,除5 mg/kg添加组母鸭钙含量和钙磷比值显著降低(P<0.05),其他各组之间差异均不显著;对公鸭,钙的含量除15 mg/kg添加组显著高于5 mg/kg添加组(P<0.05),其他各组之间差异不显著;在1~3周龄,试鸭股骨、胫骨各组各指标之间差异均不显著.4~6周龄的樱桃谷母鸭,大豆异黄酮15 mg/kg剂量组股骨湿重显著高于对照组和10 mg/kg剂量组,钙磷比值显著高于5 mg/kg剂量组(P<0.05);而对公鸭,大豆异黄酮5 mg/kg剂量组的矿物质含量显著高于其他2个添加组;对于胫骨,对照组母鸭磷的含量显著高于5,10 mg/kg添加组(P<0.05),其他各组各指标之间的差异均不显著.由此可见,大豆异黄酮对骨代谢指标有一定的调节作用,小剂量的大豆异黄酮不利于骨的形成,大剂量的大豆异黄酮能够抑制生长后期动物骨吸收,增强骨质,预防骨质疏松的发生.     

长江中下游近10年冬小麦区试主要农艺性状演变分析

利用2012—2021年间国家小麦区域试验长江中下游组212份参试品系的主要农艺性状区试结果,分析其近10年的演变规律。结果表明,该区域小麦产量和穗粒数先减后增、有效穗数明显减少、千粒重和株高不断增加、生育期基本保持平稳。今后,长江中下游麦区产量应当在保持现有产量结构的基础上,注意提高千粒重,适当降低穗粒数,培育早熟品种为主,更有利于该麦区产量提升。     

黑河上游冰沟流域4种土壤有机碳分布特征与土壤特性的关系

为了探讨黑河上游冰沟流域不同土壤有机碳分布特征与土壤特性的关系,为黑河上游冰沟流域水源涵养研究提供科学依据,采用野外采样,室内分析方法,研究了4种土壤有机碳分布特征及其与土壤特性的关系。结果表明：4种土壤有机碳含量和密度在整个土壤剖面上均表现为：森林灰褐土>高山灌丛草甸土>高山草甸土>山地栗钙土,且垂直分布均随土壤深度增加而减少,说明黑河上游冰沟流域的森林灰褐土比其它土壤更有利于土壤有机碳储存和积累。森林灰褐土0～10 cm土壤有机碳密度为4.54 kg·m^-2,略高于我国森林土壤0～10 cm土壤平均碳密度（4.24 kg·m^-2）,说明黑河上游冰沟流域的森林灰褐土区雨量充沛,林下植被丰富,凋落物现存量充足。4种土壤0～10 cm土层有机碳含量是整个土壤剖面土壤有机碳含量的30.69%～37.99%,有机碳密度是整个土壤剖面有机碳密度的29.31%～36.77%,说明黑河上游冰沟流域土壤有机碳含量和有机碳密度在表层具有很强的表聚性,不合理的人为活动引发的水土流失极易造成土壤有机碳储量的减少,应增加黑河上游冰沟流域植被覆盖度,保护生态环境,减少水土流失。4种土壤有机碳、全氮、CEC、田间持水量、团聚体在整个土壤剖面上均随土层深度增加而降低,而土壤容重、pH值在整个土壤剖面上均随土层深度增加而增大。经回归统计分析,4种土壤有机碳含量与土壤田间持水量、团聚体、全氮、CEC之间呈显著的正相关关系,与土壤容重、pH之间呈显著的负相关关系。这种变化规律与多数学者研究结果基本一致。     

Low variability of flower volatiles of Rosa damascena Mill. plants from rose plantations along the Rose Valley, Bulgaria

The composition of volatile compounds in the rose essential oils obtained from the rose flowers has been known to be affected by a number of factors including the region of rose growing. The variations of the flower volatile composition of Rosa damascena plants growing in 11 different rose plantations along the famous Rose Valley in Bulgaria were studied following GC/MS metabolite profiling. ANOVA statistical test revealed that only 14 of a total of 90 identified compounds were significantly influenced by the geographic location of the sampled rose plantation. The hierarchical clustering analysis based on the subset of these 14 compounds revealed no clear correlation between the levels of rose flower volatiles and geographic location of the studied rose plantations. The results from the study suggest low variability of rose flower volatiles accumulation and elevated plasticity of the common R. damascena genotype industrially cultivated in the Rose Valley.     

Characterization of wild plum (<Emphasis Type="Italic">Ximenia americana</Emphasis> L. var. <Emphasis Type="Italic">americana</Emphasis>; Olacaceae) fruit growing at Tepexi de Rodríguez,Puebla, Mexico

As a country, Mexico presents an especially wide range of fruit germplasm diversity. Tepexi de Rodríguez, Puebla, Mexico, belongs to The Tehuacán-Cuicatlán Valley, which is an arid zone recognized to have a flora diversity. In that place, wild plum (Ximenia americana L. var. americana; Olacaceae), locally named “tihuixocote” grows mainly in backyards, the fruit of this species is appreciated by native people due to its taste, which is reported to be a mixture between sweet and sour. Fruit from 15 trees were characterized by measuring bio-physical and bio-chemical parameters, including weight, diameter (equatorial and polar), relationship equatorial/polar diameters, total sugar, soluble solid content and phenolic compounds. The results of this study indicate variability for these various wild plum fruit characteristics among trees growing in a reduced territorial space.     

长江流域超级杂交稻产量稳定性研究

以农业部认定的6个超级杂交稻组合、3个省级主推超级杂交稻组合、2个苗头超级杂交稻组合和普通高产杂交稻汕优63(对照)为材料,研究了超级杂交稻在长江流域7个生态试验点的产量稳定性.结果表明,超级杂交稻准两优527、红莲优6号、C两优87和Y两优1号4个组合表现超高产且在各试验点产量稳定性较高,结实率高而稳定,在80%以上,表现出良好的生态适应性;其它组合则在特定的生态条件下表现较高的产量和结实率.对超级杂交稻的生态适应性及其分类进行了讨论.