Optimising cutting method and timing for the control of Abutilon theophrasti seed production

Abutilon theophrasti (velvetleaf) is a widespread and problematic annual weed. Greenhouse and field experiments were conducted to investigate the effects of different cutting methods on the viability of A. theophrasti seeds. Three cutting methods were assessed: (1) Entire plant cut and dried (EPD)—plants were cut at soil level and dried with capsules attached on the greenhouse bench or soil surface for 4 weeks; (2) capsules detached and dried (CD)—capsules were removed from plants and dried for 4 weeks; and (3) capsules detached and tested while fresh (CF)—a control treatment. Before drying, the developmental stage (stage one, dark green; stage two, light green; stage three, yellowish-green; or stage four, black with the slightly open capsule) and age (days after flowering, DAF) of each capsule was recorded. Seed viability was measured immediately in the CF treatment and after the 4-week drying period in the EPD and CD treatments. No seeds in the EPD and CD treatments were viable when harvested at the first developmental stage (1–8 DAF) in either experiment, but 100% of seeds in the CF treatment in the field were viable when harvested at 8 DAF. In both greenhouse and field experiments, seeds attained full viability at earlier harvest ages in CF than in EPD or CD treatments, suggesting that seeds might become viable relatively early in development but lose viability if allowed to dry. These findings could be applied to optimise late-season mechanical control of A. theophrasti.     

花蓟马与向日葵籽粒锈斑发生的关系

向日葵是我国重要的油料经济作物,籽粒锈斑近几年在向日葵籽粒上发生,严重影响向日葵籽粒的品质,然而关于向日葵籽粒锈斑的成因目前并不清楚。本文在内蒙古向日葵主产区,选择向日葵籽粒锈斑发生严重的区域,通过大田套袋技术并结合室内接虫试验,对向日葵籽粒锈斑的成因进行初步探索。结果表明,2020年五原县、乌拉特前旗及2021年五原县向日葵经套袋处理后,花蓟马Frankliniella intonsa Trybom的数量分别比对照降低了13.23、1.33头和191.53头,向日葵籽粒锈斑的发病率比对照(未套袋)相应降低了28.19%、12.07%和60.02%,与对照有极显著差异(P<0.01),花蓟马数量与向日葵籽粒锈斑的发病率呈现出显著的正相关关系。同时,室内在向日葵花盘上接种花蓟马后向日葵籽粒锈斑的发病率为22.67%,而未接虫的向日葵籽粒锈斑没有发病。另外,统计显示向日葵花盘外侧花蓟马数量显著大于中间和内层,向日葵籽粒锈斑发病率也呈现相同的规律。由此推测,向日葵籽粒锈斑的发生主要与花蓟马的活动有关,花蓟马可能是造成向日葵籽粒锈斑的主要成因。     

Effect of feeding Aspergillus awamori and canola seed on the growth performance and muscle fatty acid profile in broiler chicken

The aim of this study was to examine effects of dietary supplementation with Aspergillus awamori and feeding canola seed on the growth and fatty acid profile in broilers. Twenty‐eight chicks (15 days old) were assigned to the following groups: (1) control, fed a basal diet; (2) awamori, fed the basal diet supplemented with 0.05% A. awamori; (3) canola, fed a diet containing 5% canola seed; and (4) canola + awamori, fed the canola diet supplemented with A. awamori (seven birds/group). Body weight gain was increased by A. awamori but not influenced by canola seed. Breast muscle weight was increased in either awamori or canola groups. Although plasma triglyceride and cholesterol were decreased by feeding A. awamori or canola seed, fat content in the breast muscle were increased, accompanied by decrease in saturated fatty acids and increase in unsaturated fatty acids. Moreover, decreased thiobarbituric acid reactive substance and increased α‐tocopherol content in the breast muscle was observed in all experimental groups. In conclusion, these results suggested that feeding canola seed and A. awamori might improve growth performance, and modified muscle fatty acid profile and α‐tocopherol content, suggesting that they may improve meat quality.     

Effects of different forms and origins of oilseeds on dynamics of ruminal biohydrogenation of long‐chain fatty acids in vitro

Dietary unsaturated fatty acids (FA) are intensively hydrogenated in the rumen, resulting in reduced amount of poly‐unsaturated fatty acids (PUFA) and accumulation of several biohydrogenation (BH) products. In this study, BH of PUFA originating from different oilseeds (linseed, soya beans, sunflower seed and rapeseed) present in crushed oilseeds or their free oils were assessed in vitro. The assay substrates were incubated in buffered rumen fluid for 0, 6, 12 and 24 h. After incubation, the FA pattern of the incubated samples was analysed using gas chromatography. Biohydrogenation is defined as disappearance of double bonds (DB) calculated from the contents of unsaturated FA. After 24‐h incubation, the DB contents of all oilseeds were reduced (p < 0.001) by 40–60%. The reduction was higher (p < 0.001) for the crushed form compared with the oil form. In addition, linseed and sunflower seed known as oilseeds with high contents of linolenic acid C18:3 c9,12,15 (LNA) and linoleic acid C18:2 c9,12 (LA), respectively, showed a higher (p < 0.001) accumulation of the BH intermediates conjugated linoleic acid (CLA, isomer C18:2 c9t11) and vaccenic acid (C18:1 t11) for the crushed form, when compared with the oil. These results suggest an inherent effect of the physical form of the assay oilseeds on in vitro BH. Changes in FA pattern during BH in vitro can be attributed to both source and physical form of the assay oilseeds. However, further investigations are warranted to ensure whether the observed in vitro effects on ruminal BH can be confirmed in vivo.     

PEG与低温对法国百里香种子萌发的影响

以法国百里香(Thymus vulgaris)为材料,研究了PEG模拟干旱胁迫和低温对种子萌发和幼苗生长的影响,旨在探索进口百里香种子播种育苗的适宜条件。结果表明,温度、干旱及其互作对法国百里香种子萌发和幼苗生长均有显著影响。0~10%PEG-6000水分条件下,8~24℃下法国百里香种子均能良好萌发,其中在10~12℃时发芽率最高,达79.3%,显著高于其余各处理(P0.05)。当PEG-6000达15%时显著抑制其萌发,至30%PEG-6000时仅在22~24℃下少量萌发。萌发后,当温度为22~24℃,根长、茎长均显著高于其他处理。种子和幼苗生长均表现出对PEG模拟干旱胁迫和低温不同的响应。     

紫苏籽提取物对蛋鸡产蛋高峰后期生产性能、生殖激素及免疫功能的影响

为了探讨在饲粮中添加不同水平紫苏籽提取物对蛋鸡产蛋高峰后期生产性能、生殖激素及免疫功能的影响,本试验选用体重、产蛋率基本一致的48周龄海兰褐蛋鸡480只,采用单因素完全随机试验设计,随机分为4组,每组6个重复,每个重复20只。对照组饲喂基础饲粮,试验Ⅰ、Ⅱ、Ⅲ组分别在基础饲粮中添加0.01%、0.02%、0.03%的紫苏籽提取物,试验期30 d。结果表明:1)与对照组相比,饲粮中添加0.01%、0.02%、0.03%紫苏籽提取物均能降低料蛋比,但差异不显著(P0.05),4组间日均采食量、破软蛋率无显著差异(P0.05),添加0.03%紫苏籽提取物能极显著提高蛋鸡产蛋率和日均产蛋量(P0.01);2)与对照组相比,添加0.01%、0.02%、0.03%紫苏籽提取物能极显著提高蛋鸡血清中孕酮(第15天)和雌二醇(第15和30天)的含量(P0.01),添加0.03%紫苏籽提取物能极显著降低蛋鸡血清中睾酮含量(P0.01);3)与对照组相比,添加0.01%、0.02%、0.03%紫苏籽提取物能极显著提高蛋鸡血清中白细胞介素-2(IL-2)含量(P0.01),添加0.02%、0.03%紫苏籽提取物能极显著提高蛋鸡血清中免疫球蛋白G(Ig G)含量(P0.01),添加0.03%紫苏籽提取物能极显著提高蛋鸡血清中免疫球蛋白A(Ig A)含量(P0.01)。由此可知,饲粮中紫苏籽提取物添加水平为0.03%时,能极显著提高蛋鸡产蛋高峰后期产蛋率、日均产蛋量和免疫功能。     

优质杂交晚籼稻新组合乐优97的选育及栽培制种技术

乐优97是一种典型的晚籼型三系杂交水稻良种,于2022年通过中国国家农作物品种审定委员会审定,系由合肥丰乐种业股份有限公司所属的水稻研究院通过自己创制的三系不育系409A与恢复系R977 杂交选育而成的高产、优质、抗倒杂交晚籼型新型组合。文中详细尽介绍了乐优97的选育步骤,重点介绍了乐优97的特征特性,并归纳出了乐优97优质高产栽培技术及其制种技术关键要点,希望为该产品的以后大规模推广种植打下基础。     

赤霉素浓度和温水浸种时间对猕猴桃不同品种种子萌发的影响

以美味猕猴桃‘徐香’、中华猕猴桃‘宜黄2号’、毛花猕猴桃‘赣绿1号’和‘赣绿2号’4个猕猴桃品种的种子为试验材料,设置5个梯度的赤霉素浓度和5个浸种时间进行处理,通过统计种子萌发的发芽率、发芽势和发芽时滞,探讨赤霉素浓度和温水浸种时间对猕猴桃种子发芽的影响。结果表明：4种猕猴桃种子发芽率与发芽势均受赤霉素浓度和温水浸种时间的影响,其中‘徐香’的种子发芽率和发芽势最高,其次是‘赣猕1号’、‘赣猕2号’和‘宜黄2号’。‘徐香’、‘赣绿1号’和‘赣绿2号’、‘宜黄2号’种子发芽率最高所对应的赤霉素处理浓度和浸种时间组合分别为：0.6 g/L赤霉素+30 min温水浸种、0.4 g/L赤霉素+30 min温水浸种、0.6 g/L赤霉素+30 min温水浸种和0.6 g/L赤霉素+60 min温水浸种。不同品种猕猴桃发芽时滞也有一定差异,其中‘徐香’发芽最早,其次是‘宜黄2号’,‘赣绿1号’和‘赣绿2号’开始发芽最晚。