早熟玉米杂交组合主要农艺性状与产量的灰色关联度分析

应用灰色关联度分析法,对19个玉米杂交组合性状进行分析。结果表明,各性状与产量的关联度大小依次为:株高>生育期>倒折率>穗行>行粒>秃尖>含水量>百粒重>穗位高>倒伏率>穗长>出籽率>穗粗。在育种工作中应该注重对株高、生育期和倒折率的选择,同时要结合不同性状间相互关系的综合表现进行育种,使玉米产量有较大提升。     

基于表型多样性构建向日葵核心种质

为鉴定评价我国向日葵（Helianthus annuus L.）种质资源在南方地区的表现，筛选构建向日葵核心种质，以422份向日葵种质为材料，在进行2年鉴定观察的基础上，采用描述性统计、相关性分析、主成分分析等方法对11个表型农艺性状进行分析评价。结果表明，原始群体的这些农艺性状具有较大的变异幅度，其变异系数（CV）为3.60%~83.32%，平均变异系数为20.93%，其中分枝株率（0%~62.5%）、单株粒重（9.70~232.35 g）、百粒重（4.60~14.92 g）、叶片数（14.40~48.38个）和株高（103.75~260.00 cm）变异幅度较大；性状间表现出显著的相关性，主成分分析表明，影响性状的4个主要成分解释了总方差的71.72%。采用QGAstation 2.0软件构建了72组核心种质候选群体，并根据均值差异百分数（MD）、方差差异百分率（VD），极差符合率（CR）和变异系数百分率（VR），获得组获得1组包含84份材料的最佳核心种质群体。聚类分析将84份核心资源分为5大类，与原群体相比，所选核心种质均值无显著差异，方差显著提高，能最大限度代表原始油葵种质资源保存和利用。     

木醋液对桃蚜生长繁殖的急慢性效应

为了明确木醋液对桃蚜短、长期影响,以桃蚜为试虫,用100倍稀释木醋液处理小白菜饲养蚜虫,测得桃蚜繁殖发育数据。结果显示,木醋液处理显著缩短桃蚜繁殖期,而F₁代繁殖期比F₀代繁殖期延长37%;F₀代和F₁代产蚜总量与对照组相比分别降低62%和66%;处理组F₁代和F₂代的存活率比对照组降低23%和24%,但F₁代和F₂代之间差异不显著;F₁代寿命缩短25%,F₂代差异不显著。本研究证明木醋液能够缩短桃蚜的繁殖期,延长其若蚜历期,整体缩短桃蚜寿命,降低子代存活率。总之,木醋液对桃蚜的生长发育和繁殖具有一定的抑制作用,但是这种抑制作用会随着施用频次增加而逐渐减弱,即木醋液的短期效应和长期效应存在差异,所以木醋液具有开发为生物农药的价值。     

谷子株高及穗部性状主基因+多基因混合遗传模型分析

【目的】株高和穗部性状是影响谷子产量的关键性状。探究谷子株高及穗部性状表型变异的遗传规律,为相关性状的遗传改良与基因定位提供参考依据。【方法】以谷子优质品种豫谷18为共同父本,分别与黄软谷和红酒谷杂交,构建2个分别包含250个家系的重组自交系F₇群体（YYRIL和YRRIL）。采用主基因+多基因混合遗传模型,对YYRIL和YRRIL群体在2个环境下的株高、穗长、穗下节间长、穗码数、穗粒重等5个农艺性状的表型数据进行遗传分析。【结果】5个性状在所有环境中均表现连续变异且存在超亲分离现象,峰度和偏度绝对值小于1,近似正态分布,呈现数量性状的典型遗传特点。性状间相关性分析表明株高与穗长、穗下节间长在所有环境中均呈极显著正相关,穗码数与穗粒重呈极显著正相关。遗传模型分析显示YYRIL和YRRIL群体株高的最适遗传模型分别为PG-AI和PG-A多基因模型,多基因遗传率分别为95.15%和91.27%。2个群体穗码数的最适模型均为PG-AI,多基因遗传率为70.07%—71.58%。穗下节间长在2个群体的最适遗传模型分别为4MG-CEA和3MG-CEA,均为等加性主基因模型。穗下节间长在YYRIL群体的主基因遗传率为9.69%,4对主基因加性效应值相等,均为-0.34,具有负向效应;穗下节间长在YRRIL群体的主基因遗传率为45.78%,3对主基因加性效应值相等,均为1.17,具有正向效应。穗长在YYRIL群体的最适模型为MX2-ED-A,即2对显性上位主基因+加性多基因模型,主基因遗传率为43.56%,多基因遗传率为50.56%。控制穗长的2对主基因加性效应值分别为-1.21、1.68,多基因加性效应较小,为-0.0017;穗长在YRRIL群体的最适模型为MX2-AE-A,即2对累加作用主基因,加性多基因混合遗传模型;穗长的主基因遗传率为46.40%,多基因遗传率为46.91%。控制穗长的第1对主基因加性效应值为1.53,具有正向效应,第1对主基因加性×第2对主基因加性上位性互作效应值是0.60,多基因加性效应值为-0.47,表现为较低的负向遗传效应。穗粒重在YYRIL群体的最适遗传模型为MX2-ED-A;符合2对显性上位主基因+加性多基因模型,主基因遗传率为69.09%,多基因遗传率为12.08%;控制穗粒重的2对主基因加性效应值分别为0.58、5.82,以第2对主基因的加性效应为主,多基因加性效应值为-3.81。穗粒重在YRRIL群体的最适遗传模型为3MG-PEA,即3对部分等加性主基因遗传模型;穗粒重的主基因遗传率为81.10%,3对主基因加性效应值分别为-2.68、-2.68和2.66,前2对主基因的加性效应值相同,且均为负向效应。【结论】谷子株高、穗码数的最适遗传模型相似,均服从多基因遗传,遗传率较高,受环境影响较小;穗下节间长的遗传受主基因控制,主基因遗传率偏低,受环境影响较大,在栽培中应充分考虑环境因素;穗长遗传受主基因和多基因共同控制;穗粒重在2个群体均服从主基因遗传,主基因遗传率较高,可能存在主效QTL。     

豫皖小麦田麦根腐平脐蠕孢交配型基因检测

麦根腐平脐蠕孢是一种可以引起多种植物病害的病原真菌，广泛分布于世界各地，对全世界的禾谷类作物生产带来了不可估量的损失。子囊菌交配型基因具有一定的广泛性，其编码的产物是调控子囊菌有性生殖的重要转录因子。为了对河南、安徽小麦田分离获得的麦根腐平脐蠕孢群体的MAT基因型进行探索，对在河南、安徽两省不同地区分离获得33株麦根腐平脐蠕孢菌株，利用麦根腐平脐蠕孢菌的MAT特异性引物进行基因型检测，并对不同交配型代表菌株进行生长形态、孢子形态观察和致病力测定，对麦根腐平脐蠕孢菌 MAT-2基因进行了系统发育分析。结果表明，河南、安徽两省存在两种MAT基因型的麦根腐平脐蠕孢群体，含有 MAT-2基因的菌株21株，含 MAT-1基因的菌株12株，比例为7∶4（ MAT-2∶ MAT-1）。两种交配型菌株的生长形态、孢子形态和致病力无显著差异，整体分析结果与物种的分子系统学分析表现出来的亲缘关系基本一致。     

Nile tilapia broodfish fed high‐protein diets: Digestive enzymes in eggs and larvae

The aim of this study was to assess the activity of gastric, pancreatic and intestinal digestive enzymes during the embryonic and larval development of Nile tilapia (Oreochromis niloticus) GIFT strain Aqua America^® 1 obtained from a broodstock fed two levels of crude protein (CP). A total of 72 females and 24 males, 10 hapas, two CP levels (32% and 38%) and six phases of embryonic (cleavage, blastula, gastrula) and larval (hatching, 7 and 10 days post hatch, dph) stages were used. The eggs were collected in cleavage, blastula and gastrula stages, 300 mg was collected, and kept in cryogenic tubes in liquid nitrogen. For the samples at larval stage, the remaining eggs were separated according to crude protein level and kept in hatcheries and samples were collected on 7 and 10 dph the same way as before. A total of 48 samples were collected: at each protein level (32% and 38% CP), four samples were collected in each phase of embryonic and larval development. Statistical differences were not observed during embryonic development for acid proteases, trypsin, amylase and lipase activity at both levels of crude protein (32 and 38% CP). Differences for acid proteases were noticed on 7 dph; trypsin and amylase on 7 dph and 10 dph. Significant differences on blastula and 7 dph for protease; as for aminopeptidase, there was significant difference on 7 dph. The data indicated early appearance of digestive enzymes in Nile tilapia broodfish receiving 32% CP taking into account the rapid growth and development of this species.     

外源ABA对苹果砧木叶片解剖结构 及内源激素含量的影响

通过光镜和透射电镜分别观察外源脱落酸（ABA）处理下楸子（Malus prunifolia）、平邑甜茶（M. hupehensis）和新疆野苹果（M. sieversii）叶片解剖结构及叶绿体超微结构的变化，利用扫描电镜和酶联免疫法分别研究ABA处理对叶片气孔特征及其内源激素含量的影响。结果表明：与对照相比，ABA处理下楸子、平邑甜茶和新疆野苹果的叶厚分别减少了7.93%、0.25%和0.81%，栅栏组织厚度分别减少了31.43%、8.53%和4.99%（P＜0.05），海绵组织厚度分别增加了10.34%、6.14%和5.63%（P＜0.05），叶肉组织结构疏松度（SR）分别增加了19.59%、6.55%和6.50%。ABA处理下楸子和平邑甜茶的栅栏组织/海绵组织厚度比值（P/S）及叶肉组织结构紧密度（CTR）较对照显著减少（P＜0.05），其中，P/S值分别下降37.86%和13.82%，CTR分别下降25.46%和8.29%，而新疆野苹果的P/S值和CTR下降但不显著。此外，ABA处理下楸子和平邑甜茶的上表皮细胞厚度较对照分别增加了5.82%和6.43%，新疆野苹果的较对照减少了26.23%（P＜0.05）；楸子和新疆野苹果的下表皮细胞厚度较对照增加了12.09%和14.21%（P＜0.05），平邑甜茶的较对照减少了12.56%。平邑甜茶和新疆野苹果叶片上下角质层厚度较对照显著增加（P＜0.05），而楸子的变化不显著。在ABA诱导下，3种砧木的气孔密度、气孔大小（长度×宽度）及其开口度和开张比均不同程度地下降，其中，楸子的较对照分别下降了3.62%、7.12%×19.59%、67.60%和86.66%，平邑甜茶的分别下降了3.50%、4.99%×20.65%、32.42%和58.24%，新疆野苹果的分别下降了8.54%、0.92%×12.06%、20.37%和16.35%。ABA处理下3种砧木叶片细胞中叶绿体的数量变少，类囊体结构排列疏松，叶绿体上的淀粉粒趋于变小。外施ABA使3种砧木叶片内源ABA和玉米素核苷（ZR）的含量极显著增加（P＜0.01），其中楸子ABA和ZR含量比对照分别增加30.83%和13.31%，平邑甜茶的分别增加62.40%和45.28%，而新疆野苹果的分别增加了37.07%和17.06%。楸子和新疆野苹果叶片的吲哚乙酸（IAA）和赤霉素（GA）含量无显著变化，而平邑甜茶叶片的IAA及GA含量比对照分别增加了62.62%和20.62%（P＜0.01）。总之，在ABA处理下，3种苹果砧木的叶片组织解剖结构和气孔特征都发生旱生性结构变化，叶肉细胞中淀粉粒趋于变小，叶片内源ABA和ZR水平增加显著，而IAA和GA水平变化因基因型不同而存在差异。     

引进甘蔗种质资源杂交后代适应性评价

通过对引进甘蔗种质资源24个杂交后代的的10个农艺性状进行主成分分析、回归分析与通径分析,科学评价引种甘蔗种质资源在广西本地的农艺性状表现,探究各农艺性状间的协同制约关系,为甘蔗种质资源的精准评价和杂交育种材料的科学选配提供理论依据。结果表明:(1)主要农艺性状变异系数为6.79%~29.44%,24个甘蔗种质在分蘖和蔗糖产量上有较大的遗传改良潜力。(2)主成分分析将这10个农艺性状凝聚成4个主成分,分别为产量因子、有效茎因子、糖分因子和出苗因子,贡献率分别是35.2%、16.5%、15.3%、12.1%,累计贡献率达到79.1%;(3)通径分析中各性状对糖产量的直接通径系数大小依次为:蔗茎产量(0.927)>蔗糖分(0.399)>单茎重(0.039)。表明:甘蔗品种(系)GUC23-1、GUC15-2、GUC23、GUC34、GUC25在广西的丰产性最优,在甘蔗引种和选育中,考虑将蔗茎产量、蔗糖分、单茎重作为主要选择性状。     

Modern wheat cultivars have greater root nitrogen uptake efficiency than old cultivars

The availability of nitrogen (N) contained in crop residues for a following crop may vary with cultivar, depending on root traits and the interaction between roots and soil. We used a pot experiment to investigate the effects of six spring wheat (Triticum aestivum L.) cultivars (three old varieties introduced before mid last century and three modern varieties) and N fertilization on the ability of wheat to acquire N from maize (Zea mays L.) straw added to soil. Wheat was grown in a soil where ¹⁵N‐labeled maize straw had been incorporated with or without N fertilization. Higher grain yield in three modern and one old cultivar was ascribed to preferred allocation of photosynthate to aboveground plant parts and from vegetative organs to grains. Root biomass, root length density and root surface area were all smaller in modern than in old cultivars at both anthesis and maturity. Root mean diameter was generally similar between modern and old cultivars at anthesis but was greater in modern than in old cultivars at maturity. There were cultivar differences in N uptake from incorporated maize straw and the other N sources (soil and fertilizer). However, these differences were not related to variation in the measured root parameters among the six cultivars. At anthesis, total N uptake efficiencies by roots (total N uptake per root weight or root length) were greater in modern than in old cultivars within each fertilization level. At maturity, averaged over fertilization levels, the total N uptake efficiencies by roots were 292?336 mg N g^?1 roots or 3.2?4.0 mg N m^?1 roots for three modern cultivars, in contrast to 132?213 mg N g^?1 roots or 0.93?1.6 mg N m^?1 roots for three old cultivars. Fertilization enhanced the utilization of N from maize straw by all cultivars, but root N uptake efficiencies were less affected. We concluded that modern spring wheat cultivars had higher root N uptake efficiency than old cultivars.     

Assessment of short-term mortality of granary weevil,Sitophilus granarius (Coleoptera: Curculionidae) triggered by different microwave irradiation powers

Abstract

The insecticidal efficacy of microwave irradiation against the at 12, 24, 48 and 72?h following exposure to microwave irradiations (100, 300?W) and the progeny production was assessed 45?days later. Linearly increasing irradiation power range (100, 200 and 300?W) was set up for determining mortality tendency. An increase of insect mortality caused by higher irradiation period and times elapsed after treatment has become evident commencing from 12?h after the treatment, which has significantly decreased at later elapsed time after treatment. The irradiation periods inducing the highest mortality at the examined powers were at 10?min and at 100?W power (72?h: 64.93%) and at 4.5?min. and at 300?W power (12?h: 87.01). In addition, a complete suppression of progeny production was achieved by 4.5?min treatment at 300?W power. Lognormal-type mortality process was caused by the linearly increased irradiation range. The properly chosen microwave irradiation can be used for management of Sitophilus granarius larval and adult developmental stages. This treatment could provide an effective and friendly environmental treatment technique in Integrated Pest Management (IPM) program.