浅析玉米花粉和花丝活力对产量的影响

株数、每株穗数和每穗粒数是玉米产量的构成要素.随着玉米产量水平的逐渐提高,粒数作为要素之一对产量的决定作用更为突出.研究表明,玉米果穗结实粒数与雌穗吐丝小花数呈显著的正相关关系,雌穗小花能否完成正常的授粉、受精过程直接决定着果穗的结实能力,对玉米产量具有重要影响.     

Dose-effect correlation of chloride de-icing salt on Euonymus japonicus

In order to prevent severe pollution by de-icing salt on greenery along urban roads, a half lethal dose （LD_50）for a plant population was confirmed through stress simulation of chloride de-icing salt on Euonymus japonicus, with an ianalysis of physiological changes, statistics on mortality rate on plant populations and mathematic modeling during a 30- day subacute toxicity test. The results indicate that a significant positive correlation in the early stages and a significant negative correlation in the later stages were observed between the amount of chlorophyll a and b in plants and a cumulative dose of de-icing salt. The amounts of free proline in plants and the dose of de-icing salt were positively correlated Over the entire period. No significant correlation in the initial stage, but a significant negative correlation in later stages was observed between the soluble protein and the dose of de-icing salt. LDs0 of this chloride agent on E. japonicus is 5 kg.（L·m2）-1 over 30 days.     

奶牛主要饲料原料纤维物质瘤胃降解率的研究

以3头安装永久性瘤胃瘘管的荷斯坦产奶牛为试验动物,用尼龙袋法研究了奶牛常用饲料中性洗涤纤维(NDF)与酸性洗涤纤维(ADF)在瘤胃内的动态降解规律及其有效降解率.结果表明奶牛常用蛋白质饲料中豆粕与玉米蛋白粉的NDF与ADF有效降解率较高,其他饼粕均较低奶牛常用糠麸饲料中,麸皮的NDF与ADF有效降解率最高,小米糠和稻壳糠最低,几乎不降解;在奶牛常用粗饲料中苜蓿草与苜蓿草块的NDF与ADF有效降解率较高,其他粗饲料均较低.饲料NDF、ADF的有效降解率与其快速降解部分呈极显著高度正相关(P＜0.0001);与其慢速降解部分呈极显著负相关(P＜0.0001).     

桃树叶绿素含量与SPAD值呈极显著正相关

据《河北果树》2018年第6期《桃树不同区位叶片SPAD值与叶绿素含量的相关性》(作者李永红等)报道,采用SPAD-502PLUS叶绿素仪与分光光度法分别测定了桃树不同区位叶片的SPAD值与叶绿素含量,建立SPAD值与叶绿素叶绿素b和总叶绿素的二次方函数、线性函数、对数函数及乘幂函数的拟合方程,并根据决定系数(R2)确定最佳拟合曲线,以探讨SPAD值与叶绿素含量之间的关系。结果表明,桃树叶片SPAD值与叶绿素a、叶绿素b及总叶绿素含量间均存在极显著正相关关系。     

水质因子与加州鲈幼鱼生长性能相关性的研究

本文通过对北方高寒地区池塘(长春市水产品质量安全检测中心养殖基地)养殖加州鲈幼鱼鱼体生长情况的统计及其养殖池塘水质指标(总磷、总氮、氨氮、水温、溶解氧和pH值)的监测(2021年5—10月),运用Pearson相关性分析探究加州鲈幼鱼特定生长率与各水质指标之间的关系^[1]。结果表明：在一定范围内氨氮是影响加州鲈幼鱼生长的主要水质因子,水温、溶解氧和pH值与加州鲈幼鱼生长呈显著正相关(P<0.5)。本文旨在为以后加州鲈鱼在北方高寒地区的养殖和推广提供技术数据。     

不同品系杨树酚酸类物质对青杨脊虎天牛的驱避作用

运用高效液相色谱法(HPLC)测定7种不同品系杨树韧皮部中6种酚酸的含量,并观察外源施用酚酸对青杨脊虎天牛的驱避作用。结果表明,每种酚酸的含量在不同品系杨树中差异显著水平不同,被测定的6种酚酸含量之间均呈正相关关系,部分酚酸含量之间相关性达显著水平;6种酚酸对青杨脊虎天牛均有不同程度的驱避作用,其中以咖啡酸、肉桂酸、丁香酸效果更为明显,驱避率在78%以上。     

Performance of Three Adelphocoris spp.（Hemiptera： Miridae） on Flowering and Non-flowering Cotton and Alfalfa

The genus Adelphocoris（Hemiptera： Miridae） is a group of key insect pests in cotton fields in China that includes three dominant species： A. suturalis（Jakovlev）, A. lineolatus（Goeze） and A. fasciaticollis（Reuter）. Previous field surveys have found that adults of these Adelphocoris species usually move onto specific host plants when the plants enter the flowering stage. To determine the potential trade-offs for this host-plant preference behavior, the performance of these three Adelphocoris spp. on flowering and non-flowering cotton and alfalfa were compared in the laboratory. The results showed that Adelphocoris spp. had significantly higher nymphal developmental and survival rates, along with increased adult longevity and fecundity on flowering cotton and alfalfa than on non-flowering plants of either species. In addition, compared with cotton plants, alfalfa generally promoted better performance of these three Adelphocoris species, especially for A. lineolatus. Simple correlation analysis indicated that female adult longevity was positively correlated to male adult longevity and female fecundity, and female fecundity was positively correlated to nymphal development and survival rates. This study demonstrated a positive correlation between adult preference and offspring/adult performance for all three Adelphocoris species, with no evidence of any trade-offs for this preference for flowering host plants. These findings support the hypothesis that hemimetabolous insects such as mirid bugs have positive adult preference-adult/nymphal performance relationships, which is likely due to the similar feeding habits and nutritional requirements of adults and nymphs.     

苎麻产量与经济性状的相互关系

对33个苎麻品系的产量构成性状、遗传变异,遗传变异系数、遗传力、遗传进度和相关系数进行了评估。单蔸分株数和单蔸皮重表现高遗传力,而纤维产量和单蔸皮重由于基因累加效应而表现出高的遗传获得量。通过表现型和基因型两水平的研究,纤维产量与所有性状均呈正相关。本研究表明,若得纤维产量高的苎麻品种,应将单蔸皮重、单蔸株数和株高做为选择尺度。     

圆果种黄麻主要农艺性状的遗传相关及通径分析

本文通过12份圆果种品种(系)8个主要农艺性状的分析,7个性状(x)与单株干皮产量(y)的遗传相关系数都达到了显著或极显著水平,其绝对值由大到小的顺序是干茎重>茎粗>皮厚>株高>出麻率>分枝位高>分枝数。除出麻率与干皮产量呈负相关外,其余性状与干皮产量均呈正相关。干茎重对产量起着决定性的作用,而茎粗,皮厚,株高则是影响干茎重的主要性状。在选择较大干茎重的前提下,提高出率麻能较大地提高产量。     

T型杂种小麦品质及农艺性状的研究 Ⅱ、亲子相关和性状相关

用两组亲本杂交的 F_1杂种及其亲本,分析了亲子相关和性状相关.结果表明:①亲子相关 F_1株高、容重与高亲呈极显著的正相关;F_1籽粒赖氨酸含量、百克蛋白质中赖氮酸含量、抽穗期与低亲分别呈显著和极显著的正相关;F_1籽拉蛋白质含量、沉淀值与中亲呈极显著的正相关.②性状相关蛋白质亩产量与籽拉亩产量呈高度显著的正相关,与籽粒蛋白质含量亦呈正相关,但相关不显著;籽粒亩产量与千粒重、容重呈高度显著的正相关,与籽粒蛋白质含量呈显著负相关;抽穗期与千拉重、容重呈极显著的负相关;株高与千拉重呈极显著的正相关;千拉重与容重呈极显著的正相关;籽粒蛋白质含量与籽粒赖氨酸含量、湿面筋含量、干面筋含量呈极显著的正相关,与百克蛋白质中赖氨酸含量极呈显著的负相关;籽粒赖氨酸含量与湿面筋含量、干面筋含量呈极显著的正相关,与容重呈极显著的负相关;湿面筋含量与干面筋含量呈高度显著的正相关.