对两个玉米群体进行特殊配合力轮回选择的研究

对两个玉米群体完成了两轮特殊配合力的轮回选择。结果表明:两个群体一般配合力、特殊配合力和群体本身均获得了明显的遗传进展,根据原始测验种测交选择所获得的遗传增益并不因用其它测验种测配而丧失。因此,在轮选过程中,中途更换测验种仍可将群体已获得的大部分配合力遗传下去;遗传基础较丰富的群体一般配合力进展大于遗传     

5XZ-10比重式分选机气流孔板的布置优化

摘 要：种子的好坏,直接影响粮食产量,优良种子的筛选对于国家粮食安全问题具有重大意义。本文针对5XZ-10型比重式种子分选机筛面气流分布不均的问题进行单因素试验。利用 Fluent 软件,采用数值模拟与实验相结合的方法对比重式分选机气室流场进行了求解。为了简化计算量,引入多孔介质模型代替气流孔板。利用数值拟合求解了多孔介质模型参数,建立气室几何模型并验证了模型的可行性。将气流孔板布置高度比例系数α作为单因素变量,得到分选机空气流场以及空气动力场的分布特点。为获得合理的筛面气流,讨论了不同的气流孔板高度对气室出口界面气流稳定性、均匀性的影响,发现当α=0.84时,气室出口界面气流稳定性、均匀性较好。确定气流孔板合理的安装高度为530mm,为比重式种子分选机优化设计提供了试验数据以及理论依据。     

转基因作物深加工产品的DNA提取方法研究

由于转基因作物深加工产品中的DNA受到破坏,含量低、质量下降,提取困难,直接影响了后续的转基因定性检测。为解决这一难题,以酱油和番茄酱为样本进行了原料DNA提取方法的试验。针对酱油中添加大量焦糖色素和番茄酱偏酸的特点,通过加入样品预处理程序,有效地去除了酱油中的焦糖色素分子和调整了番茄酱沉淀的pH 值。利用大豆和番茄的内源特异参照基因进行PCR扩增,结果证明了利用该方法所提取的DNA完全能够满足转基因定性检测的需要,方法简单、快速、有效。     

中国南方稻田及其周边环境根结线虫种类鉴定

为了解根结线虫在中国南方稻区的分布和种类, 从15个省(直辖市/自治区)采集1 181份土样, 经生物测定发现312份土样中种植的水稻或番茄幼苗根系会产生根结, 阳性总检出率为26.42%。利用线虫特异性引物从171份阳性样品中鉴定出6种根结线虫:拟禾本科根结线虫Meloidogyne graminicola、北方根结线虫M.hapla、花生根结线虫M.arenaria、爪哇根结线虫M.javanica、象耳豆根结线虫M.enterolobii和南方根结线虫M.incognita, 分别占鉴定总样品数的88.89%、41.52%、29.82%、10.53%、4.09%和3.51%。被1、2、3、4、5、6种根结线虫混合侵染的土样比例分别为42.11%、41.52%、12.87%、2.92%、0.58%和0, 其中最常见的为拟禾本科根结线虫单独侵染(34.50%)、拟禾本科根结线虫与北方根结线虫(22.81%)或花生根结线虫(13.45%)混合侵染。本研究结果将为制定相应的传播阻断策略和防控措施提供参考。     

小麦品种周麦22号的分子遗传基础及其特异引物筛选

国审小麦品种周麦22号具有高产、稳产、多抗和广适等突出优点,是目前全国种植面积居于前列的品种,也是优异的育种亲本材料。为研究周麦22号的分子遗传学基础以及筛选周麦22的特异引物,利用覆盖小麦全基因组的340个SSR标记对周麦22号及其亲本周麦12号、温麦6号、周麦13号进行SSR标记分析。结果表明,温麦6号对周麦22号的遗传贡献最大(37.35%),其次是周麦13号(36.14%),周麦12号贡献最小(26.51%);周麦22号和其3个亲本间的遗传相似系数的聚类结果与系谱分析不一致,表明在选育过程中亲本遗传物质的传递发生了偏分离;在不同基因组水平上,3个亲本对周麦22号的遗传贡献率差异较明显,在A、B、D三个染色体组上对周麦22号的遗传贡献各有侧重;从340个SSR标记中筛选出28个周麦22号的特异标记,并通过与周麦22号的姊妹系、相似品种、衍生品种及黄淮麦区主推的小麦品种相比较,进一步筛选出1个周麦22号的特异引物Xgwm577,建立了一种能够准确、快速、简便、稳定检测周麦22号品种真实性的检测手段,为周麦22号进一步的遗传改良和推广应用提供了理论参考。     

乙唑螨腈亚致死剂量对二斑叶螨解毒酶系的影响

为明确乙唑螨腈对二斑叶螨(Tetranychus urticae Koch)体内解毒酶系的影响，采用叶片浸渍法获得乙唑螨腈对二斑叶螨的毒力回归方程，并计算出亚致死浓度LC₁₀、LC₃₀后分别处理二斑叶螨，分析60 h其体内羧酸酯酶（CarE）、谷胱甘肽-S-转移酶（GSTs）和多功能氧化酶（MFO）的比活力、米氏常数K_M及最大反应速率V_max的变化情况。结果表明：乙唑螨腈亚致死浓度对二斑叶螨体内CarE、GSTs和MFO的活性均产生诱导，且随着浓度的提高诱导增强。其中CarE的LC₁₀、LC₃₀活性最大值均出现在24 h，分别是对照的1.46、1.85倍，GSTs与MFO经LC₃₀处理后于12 h达到最大，分别是对照的1.24、1.51倍，经LC₁₀处理后最大值出现于24 h、36 h，分别是对照的1.26、1.61倍，3种解毒酶活性均随时间的延长而表现出先上升后下降的趋势。动力学参数方面，CarE的K_M值显著减小，V_max值显著增大，而GSTs和MFOs的K_M值均增大，V_max均减小，说明三者皆参与了代谢乙唑螨腈，但CarE起主导作用。因此，药剂使用时建议加入抑制CarE活性的助剂，或与抑制CarE活性的药剂混用，以提高乙唑螨腈的使用寿命和防治效果。     

不同栽培模式对四棱豆农艺性状、净光合速率日变化及品质构成因素的影响

为探讨不同栽培模式对四棱豆形态建成、生理特性及品质的影响，试验设置1个对照（露地直播）和5个处理（大棚直播、地膜直播、露地移栽、大棚移栽、地膜移栽），研究不同栽培模式对四棱豆农艺性状、净光合速率日变化及品质构成因素的影响。结果表明：四棱豆功能叶片叶面积值以大棚移栽处理最大，比叶重以露地直播处理最大。鲜豆荚总产量与单株结荚数、单株鲜豆荚重极显著相关,块根的总产量与单株块根数、单株块根重显著相关。6个处理的净光合速率日变化均表现为双峰曲线规律。种子蛋白质、Ca、Fe、VA、VC含量以露地移栽处理最大，VE含量以露地直播处理最大。可见，大棚移栽有利于四棱豆形态的建成，露地移栽有利于四棱豆品质的提高。     

Comparative advantages of chemical compositions of specific edible vegetable oils

As important supplementary to major edible oils, comparative chemical advantages of minor edible oils decide their development and usage. In this study, chemical composition of 13 kinds of specific edible vegetable oils were investigated. The comparative advantages of chemical compositions of these edible oils were obtained as follows: (1) camellia, tiger nut and almond oil were rich in oleic acid, the contents of which accounted for 79.43%, 69.16% and 66.26%, respectively; (2) safflower oil contained the highest content of linoleic acid (76.69%), followed by grape seed (66.85%) and walnut oil (57.30%); (3) perilla seed, siritch, peony seed and herbaceous peony seed oil were rich in α-linolenic acid (59.61%, 43.74%, 40.83% and 30.84%, respectively); (4) the total phytosterol contents of these oils ranged from 91.46 mg/100 ​g (camellia oil) to 506.46 mg/100 ​g (siritch oil); and (5) The best source of tocopherols was sacha inchi oil (122.74 mg/100 ​g), followed by perilla seed oil (55.89 mg/100 ​g), peony seed oil (53.73 mg/100 ​g) and herbaceous peony seed oil (47.17 mg/100 ​g). The comparative advantages of these specific edible oils indicated that they possess the high potential nutritional values and health care functions.     

PM2.5 reduction capacities and their relation to morphological and physiological traits in 13 landscaping tree species

Fine particulate matter (PM_2.5) is emerging as a serious environmental problem worldwide with the increase in anthropogenic emission sources, such as fossil fuels, transportation, and industries. In urban areas, where industrial complexes and human activities are concentrated, PM_2.5 poses a threat to human health. Recently, because of their ability to reduce PM_2.5, the introduction of landscaping trees as an environment-friendly solution has become popular; however, there remains a lack of research on the selection of species and their management. In this study, we quantified and compared the PM_2.5 reduction capacities of 13 major landscaping tree species and analyzed their relationship with the morphological and physiological characteristics of each species. The results showed that the amount of PM_2.5 reduction per leaf area differed among species and was the highest in Ginkgo biloba (28 165 ± 5353 # cm⁻² min⁻¹) and the lowest in Pinus strobus (1602 ± 186 # cm⁻² min⁻¹). Moreover, PM_2.5 reduction by the broadleaf species (18 802 ± 1638 # cm⁻² min⁻¹) was approximately 8.6-fold higher than that of the needleleaf species (2194 ± 307 # cm⁻² min⁻¹). Correlation analysis revealed that differences in PM_2.5 reduction were explained by differences in specific leaf area between species (P = 0.004) and by the length of margin per leaf area among individual trees (P < 0.05). Additionally, reduction in PM_2.5 correlated with photosynthetic properties such as maximum assimilation and carboxylation rates (P < 0.001), indicating that PM_2.5 is reduced not only by physical adsorption but also by physiological processes. These findings emphasize that for effective reduction in PM_2.5 using landscaping trees, comprehensive consideration of the morphological and physiological characteristics of the species is essential during species selection, and that continuous management is also necessary to maintain the active physiological conditions of the trees.     

蔷薇科SSR引物在云南栘［木衣］中的通用性分析

【目的】探究蔷薇科植物的SSR引物在云南栘［木衣］中的通用性，以便快速获得在云南栘［木衣］可以通用的SSR标记。【方法】以云南省瑞丽市、梁河县、陇川县和芒市4个天然居群的云南栘［木衣］为试验材料，利用100对李、梨、苹果、枇杷和Malacomeles denticulata等蔷薇科植物的SSR引物对云南栘［木衣］进行PCR扩增，从中筛选出具有多态性的SSR引物，并对云南栘［木衣］进行遗传多样性分析和聚类分析。【结果】在100对蔷薇科植物的SSR引物中有52对SSR引物在云南栘［木衣］中扩增出了目标产物条带，其中有42对SSR引物扩增出多态性条带，多态性引物所占比例为80.77%。4个云南栘［木衣］天然居群的多态位点比例、Shannon’s指数、Nei’s遗传多样性、观测等位基因数和有效等位基因数的均值分别为32.65%，0.191 7，0.131 1，1.326 5和1.232 4，其中瑞丽居群的以上多样性指数依次为40%，0.224 3，0.150 9，1.400 0和1.257 7，明显高于其他居群，表明其具有较高的遗传多样性，可能具有较为丰富的遗传变异。聚类分析结果表明，4个居群的云南栘［木衣］可分为2大类群，其中瑞丽、陇川和芒市居群聚为一类，梁河居群单独聚为一类，分类结果与地理区域分布情况一致。【结论】蔷薇科植物的SSR引物在云南栘［木衣］中具有较好的通用性，这些SSR为后续云南栘［木衣］及其近缘种进行种质资源鉴定和遗传多样性分析等研究提供了可用的标记。