Trichoderma harzianum seed treatment controls Fusarium verticillioides colonization and fumonisin contamination in maize under field conditions

In northern Italy, the most frequently occurring class of mycotoxins in maize are fumonisins, mainly those produced by Fusarium verticillioides. Currently, good agricultural practices (GAPs) represent the best line of defense for controlling the contamination of maize by Fusarium-toxins. Annual fluctuations in weather conditions can strongly reduce the advantages conferred by GAPs, and thus integration with biological control strategies can be a sustainable way to achieve reliable control of Fusarium colonization and toxin contamination. Trichoderma harzianum is a good biocontrol agent against a wide range of plant pathogens, and previous studies have reported its ability to reduce F. verticillioides colonization under greenhouse conditions. Field trials were conducted in two locations to assess the effect of seed treatment with T. harzianum strain T22 on F. verticillioides kernel colonization and on fumonisin contamination under various natural conditions. An average reduction of 58% in fungal infestation and 53% in mycotoxin contamination was observed during our three-year experiments. This research suggests that seed biopriming with T. harzianum T22 can be a promising and environmentally friendly way to control F. verticillioides kernel colonization and fumonisin accumulation.     

甜菜种子活力的测定——基于近红外高光谱技术

为保证田间甜菜种子的出苗率和生产潜力,需要在种植前对种子进行活力检测,挑选出活力高的甜菜种子进行推广种植。利用高温处理法对甜菜种子进行老化处理,再基于标准正态变换(SNV)、去趋势校正(DET)、Savitzky-Golay平滑处理(SG)、一阶差分(1D)和二阶差分(2D)5种近红外高光谱预处理方法,构建种子活力智能检测模型得出预测的种子发芽率,再利用老化处理后的甜菜种子进行发芽实验得出实际的发芽率。研究发现,甜菜种子经过一阶差分预处理建立的智能检测模型预测性能最好,其预测准确率达到91.92%。将未处理的甜菜种子的实际发芽率与一阶差分预处理法建立的智能模型预测结果进行对比,发现模型的预测准确率为88.2%。近红外高光谱技术是一种快速、无损的作物种子活力测定的新方法。     

基于气相离子迁移谱的热处理对催熟香蕉的挥发性物质分析

以香蕉果实为试验材料,利用热激、低温和催熟处理采后香蕉果实,采用气相离子迁移谱检测香蕉的挥发性物质,研究热处理对催熟香蕉果实挥发性物质的影响。结果表明:与对照相比,7 ℃ 6 d+催熟3 d和H+7 ℃ 6 d+催熟3 d 2个处理均明显降低了糠醇、苯甲醛、4-甲基苯酚、己酸乙酯、二甲基二氧杂环酮、1-戊醇、己二酮、3-甲基丁酸、2-甲氧基苯酚、2-己醇、丁酸乙酯等组分的含量;相反,这2个处理均明显增加了丙醇、乙酸丙酯、戊酮-2,3-二酮、二甲基二硫、2,3-丁二醇、甲基吡嗪、3-甲基丁酸乙酯、α-蒎烯、1-辛烯-3-醇、二甘醇二甲醚、E-2-辛烯醛、E,Z-2,6-壬醛、顺式-3-己烯醇、辛酸、庚烷-2-酮等组分的含量。另外,H+7 ℃ 6 d+催熟3 d处理明显增加了羟基丙酮、3-甲基-3-丁烯-1-醇、3-甲基-2-丁醇等组分的含量。与7 ℃ 6 d+催熟3 d相比,H+7 ℃ 6 d+催熟3 d处理明显降低了三乙胺、苯酚、2-戊酮、2-戊基呋喃、癸醛、E-2-辛烯醛、甲硫基丙醛、2-己醇、2,3,5-三甲基吡嗪等组分的含量,导致这些组分含量与对照基本一致。进一步研究发现,热处理能明显降低7 ℃冷藏香蕉果实的冷害指数,减轻香蕉果实的冷害症状。热处理诱导催熟香蕉果实上述挥发性物质的变化,可能与热处理诱导香蕉果实产生抗冷性的过程密切相关。     

浙江山茶花病虫害防治初探——以景山茶花专类园为例

温州景山公园茶花园内茶花丰富，茶花开放时间从1 1月左右陆续开放至来年5月，花期时间长、花色艳丽、花型丰富。通过对温州景山茶花园茶花病虫害进行记录，结合防治，提高茶花开花期品质和赏花品质。     

沈抚灌区耕地重金属Cd、Pb的变化特征分析

选择沈抚灌区东部13个自然村庄的农业种植区，以1500 m间距网格化布点29处，调查研究区历史耕作情况，选取18个停灌时间不同的耕地样点，每个样点按0~20、20~40、40~60 cm采集3层土壤样品，分析测定重金属Cd、Pb的全量及化学形态，并测定了地上作物的茎叶、籽粒中重金属含量，探究研究区不同停灌时间及利用类型耕地土壤中Cd、Pb的分布特征及变化规律。结果表明：0~20、20~40、40~60 cm土壤中Cd含量分别为0.65~1.57、0.66~1.18、0.61~1.18 mg·kg^-1，停灌20~25年的土壤0~20 cm土层Cd含量最高，为1.57 mg·kg^-1；各土层Pb变化范围分别为21.07~38.59、14.97~30.59、15.71~25.66 mg·kg^-1，未随停灌时间发生明显变化；Cd在20~40、40~60 cm土层迁移率分别为0.42~0.50、0.46~0.52，而Pb仅为0~0.34、0~0.68；玉米茎叶、籽粒中Cd含量分别为0.33~0.47、0.02~0.07 mg·kg^-1，水稻茎叶、籽粒中Cd含量分别为0.33~0.89、0.02~0.09 mg·kg^-1，Pb含量分别为1.51~2.32、0.47~0.62mg·kg^-1，Cd、Pb在作物茎叶、籽粒中未随不同耕作方式及停灌时间表现出明显差异；水田土壤可交换态Cd含量占总量的37.33%，旱田可交换态Cd含量占总量的7.82%~13.95%；水田土壤可交换态Pb含量占总量的9.03%，旱田占总量的0.87%~4.18%。研究结果可为重金属污染耕地的利用管理及污染修复提供依据。     

Preharvest application of methyl jasmonate (MeJA) in two plum cultivars. 1. Improvement of fruit growth and quality attributes at harvest

Two plum (Prunus salicina Lindl.) cultivars ‘Black Splendor’ (BS) and ‘Royal Rosa’ (RR) were treated with methyl jasmonate (MeJA) at 3 concentrations (0.5, 1.0 and 2.0 mM) along the on-tree fruit development: 63, 77 and 98 days after full blossom (DAFB). On a weekly basis, fruit samples were taken for measuring fruit size and weight and parameters related to quality. Results revealed that MeJA was effective in increasing fruit size and weight, the 0.5 mM being the most effective for BS cultivar and 2.0 mM for RR. At harvest, those fruit treated with 0.5 mM MeJA had the highest firmness and colour Hue values. Total acidity was also generally higher in MeJA-treated fruit than in controls, while the content of total soluble solids remained unaffected. In addition, total phenolics and total antioxidant activity were found at higher concentrations in 0.5 and 2.0 mM MeJA-treated than in control fruit over at last 3 weeks of fruit development for BS and RR cultivars, respectively. Overall results suggest that MeJA could be a promising preharvest tool to increase plum size and quality with enhanced bioactive compounds and antioxidant activity, although the optimum concentration is cultivar dependent.     

猪支原体肺炎诊断与处理

猪支原体肺炎是生猪养殖中较为常见的一种猪肺疾病类型,该病具有高度接触性、慢性传染性等特点,如果未能得到及时有效的处理则会扩散至整个生猪群体范围,对生猪养殖的经济效益造成严重损害。且在猪支原体肺炎的发生中,该病经常与圆环病毒及其他病原体进行混合感染,进一步加深生猪病情,对生猪养殖造成非常严重的经济损失。养殖人员在生猪养殖中务必要加强对于猪支原体肺炎的重视程度,积极了解猪支原体肺炎的临床症状与发生特点,采取有效的防治措施以避免猪支原体肺炎发生。该文主要论述猪支原体肺炎的发生特点、临床症状以及诊断防治。     

以Lorke法为基础的半致死剂量(LD50)分析方法在油酸、化香树果序、黄连素抗镉减毒评价中的应用

镉污染严重着威胁农业的健康发展,如何有效抗镉减毒是保障农业生产安全的重要措施,然而目前缺乏高效的抗镉药物及简便易行的评价方法。本实验借助Lorke法为基础的半致死剂量(LD50)分析方法,检测了油酸、化香树果序、黄连素等不同潜在的抗镉化合物的减毒作用。通过改良后的Lorke法测定不同抗镉药物对小鼠的径口镉LD50的影响。结果显示,与200mg/kg维生素C相比,在灌胃200mg/kg油酸、化香树果序、黄连素能够减轻镉的毒性,提高镉的LD50。对照的LD50由140-160mg/kg分别上升至300-320mg/kg(油酸组),280-300mg/kg(化香树果序组)和320-340mg/kg(黄连素组)。以上结果表明,以Lorke法为基础的LD50分析方法,能够评价出油酸、化香树果序、黄连素的减镉毒作用,及其剂量-效应关系。以上结果同时证明了相同剂量下黄连素效果要优于油酸、优于化香树果序。     

奶牛乳腺炎防治方法的研究进展

综述了传统及现代防治乳腺炎的方法,如注射、激光、中草药疗法等。同时,概述了国内外新型制剂和乳房炎的预防措施。