刈割次数对苜蓿相关表型性状与饲草产量的影响

试验选取4份苜蓿材料,设4次刈割处理,观察测试表型性状及干物质的变化动态,并用DPS7.05数据处理系统对各性状指标与饲草产量的关系进行计算分析,以探讨刈割次数对苜蓿表型性状及饲草产量的影响,为高效优质生产提供依据。结果表明,刈割频度显著影响苜蓿越冬率(P<0.05),苜蓿株高、茎粗、茎叶比、分枝数等指标均随刈割次数增加呈明显降低趋势,其中WL525苜蓿首次刈割与其他3次刈割时的株高、茎粗均呈现显著性差异(P<0.05),茎叶比差异性不显著(P>0.05);而苜蓿饲草产量则随刈割次数增多而增加,与刈割1次的情况相比,WL525苜蓿刈割4次后产量增量最多,达1885kg/hm₂;4次刈割后试验材料饲草总产量从高到底的次序依次为WL525>WL903>赛迪>惊喜。全部材料中与饲草产量关联度最大的指标为株高和茎粗,其中株高与惊喜苜蓿饲草产量的关联系数最大,达0.3751;茎粗与WL525苜蓿、WL903苜蓿饲草产量的关联系数最大,分别为0.2854、0.1944。     

陆地棉新品种生物学特性与品质特性鉴定结果分析

对2016-2017年引进的62个陆地棉新品种进行了形态特征、生物学特性和品质特性的鉴定及分析。结果表明：目前收集的新材料以中早熟棉为主,铃重以中等大小为主,衣分中等,悬殊较大,马克隆数值普遍偏大。     

木枣抗裂变异系的鉴定和果实性状分析

在枣品种的抗裂性调查中，发现“木枣”存在变异系。本研究以“木枣”、变异系“V1”、变异系“V2”和易裂品种“狗头枣”为供试材料，在采用冷水浸泡法进行室内裂果率测定和抗裂性分析的基础上，对单果重、果纵茎、果横茎、果纵横茎比、单核重、核纵茎、核横茎、核纵横茎比、梗洼宽度、肉核比、含水量等果实性状进行了测定。结果表明：裂果率表现为狗头枣>V1≈木枣>V2，筛选出木枣优良抗裂变异系V2，与木枣遗传背景一致，抗裂性又极显著优于木枣，可为后续裂果机理研究和抗裂品种选育提供育种材料。品种的抗裂性与果形、核形、肉核比、梗洼宽度有关。果实较小、果核较小、果形细长、肩大尾尖、肉核比高、梗洼宽度大，抗裂性好。     

茶树品种峨眉问春和川茶2号新梢主要生化成分分析

为了解峨眉问春和川茶2号在四川茶区的产量及鲜叶品质,以福鼎大白茶为对照,对翠屏、沐川、名山茶区的峨眉问春和川茶2号的芽叶性状和主要生化成分进行测定。结果表明:三地的峨眉问春芽叶较长较重,发芽密度与对照相当;其春、夏梢的茶多酚、儿茶素和咖啡碱含量均显著(P<0.05)高于对照,游离氨基酸总量均显著(P<0.05)低于对照。川茶2号芽叶较重实,发芽密度显著(P<0.05)高于对照;其春、夏梢的水浸出物含量和游离氨基酸总量均显著(P<0.05)高于对照,茶多酚、儿茶素含量及酚氨比均显著(P<0.05)低于对照;其春梢的茶氨酸、鲜爽味氨基酸含量及儿茶素品质指数均显著(P<0.05)高于对照,儿茶素苦涩味指数均显著(P<0.05)低于对照。峨眉问春和川茶2号在三地均表现出高产潜力及较好的适应性。川茶2号具有鲜爽、苦涩味轻的生化物质基础,可开发高档名优绿茶,可在四川全省茶区推广。峨眉问春鲜叶品质不及对照,可在川南早茶产区进行适度推广。     

Screening of antagonistic Trichoderma strains and their application for controlling stalk rot in maize

Maize is one of the major crops in China, but maize stalk rot occurs nationwide and has become one of the major challenges in maize production in China. In order to find an environment-friendly and feasible technology to control this disease, a Trichoderma-based biocontrol agent was selected. Forty-eight strains with various inhibition activities to Fusarium graminearum, and Fusarium verticillioides were tested. A group of Trichoderma strains(DLY31, SG3403, DLY1303 and GDFS1009) were found to provide an inhibition rate to pathogen growth in vitro of over 70%. These strains also prevented pathogen infection over 65% and promoted the maize seedling growth for the main root in vivo by over 50%. Due to its advantage in antifungal activity against pathogens and promotion activity to maize, Trichoderma asperellum GDSF1009 was selected as the most promising strain of the biocontrol agent in the Trichoderma spectrum. Pot experiments showed that the Trichoderma agent at 2–3 g/pot could achieve the best control of seedling stalk rot and promotion of maize seedling growth. In the field experiments, 8–10 g/hole was able to achieve over 65% control to stalk rot, and yield increased by 2–11%. In the case of natural morbidity, the control efficiency ranged from 27.23 to 48.84%, and the rate of yield increase reached 11.70%, with a dosage of Trichoderma granules at 75 kg ha~(-1). Based on these results, we concluded that the Trichoderma agent is a promising biocontrol approach to stalk rot in maize.     

Relationships between body size and secondary sexual characters,and sperm characters in male Dolly Varden char (Salvelinus malma)

In Salmonidae, subordinate males are exposed to higher risks of sperm competition than dominant males and thus are expected to improve the sperm characteristics (sperm concentrations, sperm velocity and sperm longevity). In this study, we investigated the relationships between body size and secondary sexual characters (breeding colour, hump height and snout length), and sperm characteristics of one‐year‐old (newly matured) Dolly Varden char. Small males displayed higher sperm concentrations than large males. Moreover, males with dull breeding colours, but not with lesser snout length and hump height, displayed an increased sperm velocity compared to males with bright colours, suggesting a trade‐off between sperm quantity and the investment in breeding colour. In addition, sperm longevity decreased as sperm swimming velocity increased. These findings indicate that small males with dull breeding colours improve the quantity and quality of their sperm to a great extent to enhance their chances of reproductive success.     

异速对辊式玉米秸秆粉碎还田装置设计与试验

针对玉米秸秆量大、韧性强,导致还田后秸秆粉碎不均匀影响后续整地和播种等问题,该研究提出了一种异速对辊及动态双支撑形式的玉米秸秆粉碎还田方式,并研制了相应的玉米秸秆还田装置,主要由捡拾粉碎单元、对辊滑切支撑单元、支撑板和机壳等组成。在异速动态双支撑条件下,通过对作业过程中玉米秸秆动力学分析和秸秆漏捡面积分析,对捡拾粉碎刀和对辊滑切支撑刀进行设计,建立了影响秸秆粉碎合格率的数学模型。以捡拾粉碎刀转速、L型甩刀折弯角、L型甩刀刃口长度和滑切支撑刀滑切角为因素,秸秆粉碎合格率为试验指标进行Box-Behnken试验。田间试验结果表明:当滑切支撑刀滑切角45°、捡拾粉碎刀转速1 700 r/min、L型甩刀刃口长度45 mm和L型甩刀折弯角40°时,玉米秸秆粉碎合格率为92.58%,与预测值误差5%,满足国家标准要求。该研究提出的秸秆粉碎还田方式和研制的秸秆粉碎装置为玉米秸秆粉碎还田机设计和优化提供新的方案和技术支撑。     

秸秆还田配施腐熟剂对砂性土壤性质及滴灌玉米生长的影响

为探究秸秆还田配施腐熟剂对宁夏扬黄灌区土壤改良和玉米增产的效应,在秸秆还田条件下施用3种不同腐熟剂[生物秸秆速腐剂(SR+BS)、EM菌秸秆腐熟剂(SR+RJ)、有机废物发酵菌曲(SR+OW)],以秸秆还田不施腐熟剂处理为对照(CK),研究其对秸秆生物失重率、砂性土壤理化性状和滴灌玉米生长及产量的影响。结果表明,3种腐熟剂均能有效促进玉米秸秆腐解,其中SR+RJ的秸秆腐解程度最佳,翻埋130 d后其秸秆生物失重率为49.9%,SR+OW和SR+BS次之,3种处理分别较CK显著提高7.1、5.7、5.2个百分点。SR+RJ对改善0~40 cm土层土壤容重效果最佳,较CK显著降低4.2%,同时显著提高了耕层土壤有机质和速效养分含量及生育中后期土壤贮水量,SR+OW和SR+BS次之。施用秸秆腐熟剂能明显促进玉米生育中后期植株生长,其中SR+RJ最佳。SR+RJ和SR+OW对玉米增产增收效果最明显,分别较CK显著增产26.9%、23.4%,显著增收28.8%、23.4%。可见,秸秆还田配施腐熟剂可有效促进玉米秸秆腐解,改善土壤理化性质,促进玉米生长发育,显著提高作物产量与经济效益,以EM菌秸秆腐熟剂效果最佳。本研究为宁夏扬黄灌区还田后促进秸秆腐熟和砂性土壤培肥及玉米高产提供了技术参考。     

14种悬浮种衣剂防治玉米地下害虫、蚜虫和茎基腐病的防效评价

摘 要：为有效控制玉米地下害虫、蚜虫和茎基腐病的常年危害，筛选具有较好控制作用的种衣剂，笔者开展了14种悬浮种衣剂田间药效试验。试验表明：14种种衣剂对供试玉米品种出苗安全；氟虫腈?噻虫嗪（30%悬浮种衣剂）(1:1000)处理的出苗率96.7%为最高值。氟虫腈?噻虫嗪（30%悬浮种衣剂）(1:1000)对玉米地下害虫、玉米蚜虫的防治效果分别达84.8%、80.0%。精甲?咯?嘧菌（11%悬浮种衣剂）(1:2000)对玉米茎基腐病的防治效果达73.7%。说明以噻虫嗪、氟虫腈和甲霜灵为主的复配防治玉米地下害虫、蚜虫、茎基腐病，能够取得较好的防治效果。建议针对不同的生态类型区域，结合品种、施肥、管理等措施选用不同的配方，以取得最佳的防治效果。     

不同生物刺激剂对鲜食玉米产量和品质的影响

为研究生物刺激剂对玉米的增产提质效果,试验探讨不同生物刺激剂对玉米的产量和品质方面的影响,为鲜食玉米的优质高产栽培提供技术支撑。以鲜食玉米‘钱江糯3号’为试验品种,以3种生物刺激剂（阿美滋、美基、保康灵1号）为供试药剂,设置6个处理（阿美滋1000倍液、阿美滋1500倍液、阿美滋2000倍液、美基3000倍液、保康灵1号300倍液、清水对照）,研究大田常规施肥水平下药剂对‘钱江糯3号’的经济性状、产量及品质的影响。在阿美滋1500倍液喷施下,玉米的行粒数、单穗鲜重和单穗净重、产量均最高,蛋白质含量、粗纤维含量、还原糖含量、淀粉含量均居第3位;在保康灵1号300倍液喷施下,玉米的穗粗最高,单穗鲜重、单穗净重、产量均居第2位,蛋白质含量最高,脂肪含量最低,还原糖含量居第2位。阿美滋1500倍液在增加玉米产量上是最佳选择,保康灵1号300倍液则对提升玉米品质最有效果。建议生产上将阿美滋1500倍液与保康灵1号300倍液配合施用,这对鲜食玉米的增产提质效果最好。