Optimizing herbicidal efficacy of glyphosate isopropylamine salt through ammonium sulphate as surfactant in oil palm (Elaeis guineensis) plantation in a rainforest area of Nigeria

A randomized complete block field trial was conducted over 2 years to evaluate the herbicidal efficacy of glyphosate isopropylamine salt (Roundup^®) applied singly at 1.41 kg a.e. ha⁻¹ or in combination with ammonium sulphate (AMS) as surfactant at 0.5, 1.0, 1.5, and 2.0% (wt/v) in a 5-year old oil palm plantation of the Federal University of Technology, Akure located in the rainforest vegetation zone of Nigeria. Assessment of herbicidal efficacy based on the Henderson-Tilton formula indicated that glyphosate applied singly or in combination with varying concentrations of AMS proved highly effective in controlling most of the grasses and broadleaved weeds prevalent in the experimental plots. Herbicidal efficacy on total weed density, weed fresh weight as well as on weed dry weight was found to increase in the order of increasing concentration of AMS. Regressing percentage herbicidal efficacy (Y) against increasing concentration levels of AMS (X) indicated significant (P0.001) positive relationships with an average correlation coefficient (r) of +0.95 in both years. These results confirm the potential of AMS as an effective surfactant that can be exploited in glyphosate-based weed management schemes in the sub-humid tropical environment.     

连作晚稻前期施药种类和时间对褐飞虱种群动态的影响

 田间试验研究了连晚前期施药种类和时间对褐飞虱种群动态的影响。结果表明施药后褐飞虱种群数量均有不同程度下降，但对褐飞虱主害代的控制作用与使用的农药种类和时间有密切的关系，而农药对褐飞虱的控制作用随种群的发展而下降。施药区褐飞虱种群增长倍数较对照区显著提高，其主要原因是农药对天敌尤其是对微蛛和黑肩绿盲蝽的杀伤作用。引起褐飞虱种群增长倍数提高的主要时期在四代成、若虫高峰期至五代卵高峰期，即施药后2～3周内。在各种供试药剂中，施用三唑磷的小区明显出现再增猖獗现象．根据以上结果，讨论了改善褐飞虱化学防治的途径。     

Verification of Glyphosate Resistance,Lepidopteran Resistance and Wide Compatibility of Male Sterile Line E1C4008S in Rice

Weeds and insect pests are two important biotic stresses resulting in yield loss in rice, and wide compatibility is the essential characteristic of breeding inter-subspecific hybrid rice. This study focused on glyphosate resistance, lepidopteran resistance and wide compatibility as well as identification of molecular and some agronomic characteristics of transgenic male sterile line E1 C4008 S. The results indicated that glyphosate resistance gene Epsps# and lepidopteran resistance gene Cry1 ca~# were transferred into japonica wide compatibility male sterile line 4008 S by Agrobacterium-mediated method, and four independent transformation events named E1 C4008 S-1, E1 C4008 S-2, E1 C4008 S-3 and E1 C4008 S-4 were obtained, in which E1 C4008 S-3 and E1 C4008 S-4 were of single copy insertion. The EPSPS protein contents of E1 C4008 S-3 and E1 C4008 S-4 in different organs were significantly different both in descending order of leaf stem root, and ranged from 300.58 to 1410.69 μg/g at the tillering stage. The glyphosate tolerable concentration(dosage) of E1 C4008 S-3 and E1 C4008 S-4 reached at least 16 g/L(54.42 kg/hm2), and the seeds of E1 C4008 S-4 can germinate normally on the medium containing 1 g/L glyphosate. The CRY1 C protein contents of E1 C4008 S-3 and E1 C4008 S-4 in different organs were significantly different both in descending order of leaf stem root, and ranged from 0.62 to 2.43 μg/g at the tillering stage. The larvae mortalities of rice leaf rollers fed on leaves of E1 C4008 S-3 and E1 C4008 S-4 for 5 d were 95.35% and 97.77%, respectively, while the average mortalities of silkworms fed with protein extracts from leaves of E1 C4008 S-3 and E1 C4008 S-4 reached 94.55% and 83.64%, respectively. The results suggested that wide compatibility and evaluated agronomic traits of E1 C4008 S-4 were not significantly changed by insertion of the exogenous genes. Overall, a novel male sterile germplasm with glyphosate resistance, lepidopteran resistance and wide compatibility was verified to be developed in rice.     

遗传算法率定参照作物腾发量相关参数的研究

用气象资料计算参照作物腾发量(ET0)的方法需要各种气象(候)和物理参数,净辐射是其中的重要数据之一,而专业测量净辐射的设备在农业气象站里很少安装。为解决计算ET0时缺少太阳净辐射(Rn)测量值这一实际问题,该文采用浑善达克沙地东南缘南沙梁草甸草原区气象站观测的气象资料,用遗传算法模型对联合国粮农组织56号文本(FAO56)推荐值(as和bs)进行率定,计算了对应夏半年(4—9月)和冬半年(1—3月和10—12月)的太阳净辐射和参照作物腾发量,并将率定前后的模拟太阳辐射进行对比分析,用残差估计指数法对该方法模拟的参照作物腾发量模拟精度进行了分析。结果表明:在缺少太阳净辐射测量值的地区,采用FAO56参数(as和bs)推荐值与遗传算法模型率定参数(as和bs)相比,净辐射年内变化趋势一致,采用率定后参数计算的净辐射相对更不稳定,波动更大,但能有效提高参照作物腾发量计算精度。误差较大的模拟值均出现在降雨日前后,降雨虽然并未直接出现在Penman-Monteith公式中,但是降雨必然会对湿度和温度等气象条件造成一定影响,而as和bs是受湿度等因素影响而变化的,其深层次的原因有待进一步分析。     

利用GGE双标图和综合选择指数划分棉花品种生态区

为提高农作物品种多性状选育和应用的可靠性,本研究基于品种选择指数,应用GGE双标图进行了棉花品种生态区划分。首先依据国家棉花品种审定标准构建通用性强的品种选择指数(SI),即SI=0.40×皮棉产量+0.13×纤维比强度+0.09×(纤维长度+马克隆值)+0.11×枯萎病+0.09×黄萎病+0.10×霜前花率。然后,采用GGE双标图方法对2000—2013年期间39组(含585个单点试验)长江流域国家棉花区域试验中品种选择指数的基因型与环境互作效应及环境间关系进行综合评价与分析。研究结果将长江流域棉区划分为四川盆地生态区、南襄盆地生态区、浙江省沿海生态区和长江中下游生态区。其中,长江中下游生态区为长江流域的主要品种生态区,对长江流域的总体环境代表性最强,涵盖了湖南省环洞庭湖棉区、湖北省江汉平原和鄂东南岗地棉区、江西省环鄱阳湖棉区、安徽省沿江棉区、江苏省宁镇丘陵及沿江和沿海棉区;四川盆地生态区、南襄盆地生态区和浙江省沿海生态区均为特殊生态环境条件下的品种生态区,对总体环境代表性较差。因此,将以长江流域棉区为广谱适应性育种目标环境的棉花品种综合性状选择试验优先安排在长江中下游生态区中,有利于提高育种的总体选择效果,而其余品种生态区不适宜作为以长江流域为目标环境的品种综合性状选择环境,可侧重于特殊适应性品种选育。本研究充分展示了GGE双标图在品种生态区划分方面的应用效果,合理划分了长江流域基于选择指数的棉花品种生态区,可为长江流域棉区的品种多性状选择和推荐策略提供决策依据,也为其他棉区和作物品种生态区划分提供参考。     

中国气候变化对农作物育种策略影响探究

气候变化直接影响农作物产量,根据生产实际和气候特征,因地制宜选育农作物新品种,对保障中国粮食安全具有重要的意义。本文利用1979—2014年中国粮食主产区和西北地区气象站点数据及粮食产量数据,通过进一步的统计分析,明确粮食产量与气候变化特征。结果表明：中国东北地区、黄淮海地区、长江流域地区和西北地区年平均气温增幅均值分别为0.30℃/10 a、0.37℃/10 a、0.38℃/10 a和0.48℃/10 a,与粮食产量相关性显著;年平均气温空间上从南到北、从东到西呈降低趋势;由于热量资源分布不均导致各地区年降水量变化差异显著,但与粮食产量相关性不显著。粮食作物应以优质、高产、多抗以及适宜于机械化生产为原则,采用传统育种和现代分子生物学技术相结合的育种策略,重点提高东北地区水稻品种的耐涝性和抗倒性,黄淮海和长江流域地区水稻品种的耐高温性,西北地区晚稻品种的耐低温性,以及各地区小麦和玉米品种的耐旱性。     

谷子收获机风筛式清选装置试验分析

为了减少谷子联合收获的清选损失,对谷子收获机风筛式清选装置进行了试验分析。运用参数可调的风筛式谷子清选装置,以清选风速、风向、筛分振幅和曲柄转速为试验因素,以籽粒损失率和含杂率为试验指标,对谷子联合收获机脱出物进行了清选试验。试验结果表明:籽粒损失率随清选风速、筛分振幅、曲柄转速的增大而增大,随清选风向角度的增大呈先增大后减小再增大趋势;含杂率随清选风速、筛分振幅、曲柄转速的增大而减小,随清选风向角度的增大呈先减小后增大再减小趋势;最优清选工作参数为清选风速4.19 m/s、清选风向30.3°、筛分振幅22 mm和曲柄转速218 r/min,籽粒损失率为2.02 %,含杂率为8.01 %。该研究为谷子联合收获机清选装置结构与工作参数设计提供参考。      

Resistance to root-lesion nematode Pratylenchus neglectus identified in a new collection of two wild chickpea species (Cicer reticulatum and C. echinospermum) from Turkey

Chickpea (Cicer arietinum) is a major legume crop, with Australia being the second largest producer worldwide. Pratylenchus neglectus is a root-lesion nematode that invades, feeds and reproduces in roots of pulse and cereal crops. In Australia, chickpea and wheat (Triticum aestivum) are commonly grown in rotation and annual damage by P. neglectus accounts for large economic losses to both crops. Cultivated chickpea has narrow genetic diversity that limits the potential for improvement in resistance breeding. New collections of wild chickpea species, C. reticulatum and C. echinospermum, have substantially increased the previously limited world collection of wild Cicer germplasm and offer potential to widen the genetic diversity of cultivated chickpea through the identification of accessions with good resistance. This research assessed 243 C. reticulatum and 86 C. echinospermum accessions for response to P. neglectus in replicated experiments under controlled glasshouse conditions from 2013 and 2014 collection missions that were received, tested and analysed in two experimental sets. Multi-experiment analyses showed lower P. neglectus population densities in both sets of wild Cicer accessions tested than Australia's elite breeding cultivar PBA HatTrick at the significance level p < 0.05. Provisional resistance ratings were given to all genotypes tested in both experimental sets, with C. reticulatum accessions CudiB_008B and Kayat_066 rated as resistant in both Set 1 and Set 2. New sources of resistance to P. neglectus observed in this study can be introgressed into commercial chickpea cultivars to improve their resistance to this nematode.     

绿肥作物矿化分解对土壤镉有效性的影响研究进展

绿肥是一种生物有机肥,其矿化分解是绿肥作物翻压进入土壤中被微生物分解产生植物可直接利用的物质的过程。绿肥矿化分解可影响土壤镉（Cd）有效性,但绿肥与Cd有效性两者并非简单的线性相关。本文综述分析了绿肥作物矿化分解对土壤Cd有效性的影响及其作用机理。结果表明：在绿肥翻压进入土壤被微生物分解的过程中,土壤中的可溶性有机质、pH值与Eh值、铁还原和微生物群落均影响重金属Cd在土壤中的迁移,可以使重金属Cd固定在土壤中或在植物根系表面沉淀;作物细胞拦截可降低Cd向地上部分的转运,最终只有极少量Cd到达作物的可食用部分。但由于受到绿肥用量、作物品种、土壤理化性状等其他因素的干扰,绿肥对土壤中Cd的修复效果具有不确定性。最后,通过总结分析绿肥对土壤性质的影响和其他因素对绿肥的干扰,阐明了绿肥对土壤中Cd有效性的影响机制。