Carbohydrate and crude protein fractions in perennial ryegrass as affected by defoliation frequency and nitrogen application rate          下载免费PDF全文

P. A. Loaiza  O. Balocchi  A. Bertrand 《Grass and Forage Science》2017,72(3):556-567

The objective of this study was to evaluate the effects of defoliation frequency (either at two‐ or three‐leaf stage) and nitrogen (N) application rate (0, 75, 150, 300, 450 kg N ha^?1 year^?1) on herbage carbohydrate and crude protein (CP) fractions, and the water‐soluble carbohydrate‐to‐protein ratio (WSC:CP) in perennial ryegrass swards. Crude protein fractions were analysed according to the Cornell carbohydrate and protein system. Carbohydrate fractions were analysed by ultra‐high‐performance liquid chromatography. Sward defoliation at two‐leaf stage increased the total CP, reduced the buffer‐soluble CP fractions and decreased carbohydrate fractions of herbage (P < 0·001). The effect of defoliation frequency was less marked during early spring and autumn (P < 0·001) than for the rest of the seasons. An increase in N application rate was negatively associated with WSC, fructans and neutral detergent fibre (P < 0·001), and positively associated with CP and nitrate (N‐NO₃) contents of herbage. Nitrogen application rate did not affect CP fractions of herbage (P > 0·05). The fluctuations in CP and WSC contents of herbage resulted in lower WSC:CP ratios during early spring and autumn (0·45:1 and 0·75:1 respectively) than in late spring (1·11:1). The herbage WSC:CP ratio was greater (P < 0·001) at the three‐leaf than the two‐leaf defoliation stage and declined as the N application increased in all seasons (P < 0·001). The results of this study indicate that CP and carbohydrate fractions of herbage can be manipulated by sward defoliation frequency and N application rate. The magnitude of these effects, however, may vary with the season.  相似文献   

病程相关蛋白在采后果蔬诱导抗病性中的研究进展     

焦文晓  王晓梅  范新光  姜微波 《保鲜与加工》2020,20(1):206-211

果蔬受到真菌、细菌或病毒侵染时,自身能诱导产生病程相关蛋白(Pathogenesis-related proteins,PRs)。根据它们的结构亲缘关系和生物活性,PRs被分为17个功能家族。在控制果蔬采后病害的研究中,利用激发子诱导产生果蔬抗性已逐渐成为果蔬采后病害防治中一种安全、高效的保鲜方法,这也成为果蔬采后抗病研究的热点和发展趋势。本文综述了果蔬病程相关蛋白的分类、功能、诱导表达,以及蛋白组学技术在果蔬采后PRs表达水平上的应用,以期为果蔬病程相关蛋白的研究提供借鉴和参考。  相似文献   

不同施肥处理对枳及柠檬容器苗生长的影响     

董美超  朱进彬  丁望可  李进学  刘佳兴  赖新朴  王自然  杨世品  高俊燕 《热带作物学报》2017,38(6):1010-1015

研究9个不同施肥处理对枳及柠檬容器苗生长的影响。结果表明:不同施肥处理对枳容器苗的苗高、地径、分枝高度及嫁接后柠檬苗的发芽率、株高、茎粗、分枝数及生物量都存在显著差异;不同施肥处理对枳及柠檬容器苗综合表现最好的为T4(撒施柠檬专用肥1.6 g)处理,其次是T2(撒施尿素0.6 g)、T3(撒施柠檬专用肥0.8 g)处理,表现最差的是T8(浇施5%柠檬专用肥)和T7(浇施3%柠檬专用肥)处理。在一定施肥浓度范围内,施肥对嫁接后柠檬容器苗的生物量积累有明显促进作用。柠檬容器苗培育时建议采用在基质中撒施柠檬专用肥1.6 g。  相似文献   

青霉菌发酵液对大豆幼苗生长及生理特性的影响   总被引：1，自引：0，他引：1  

陶波  张健  韩玉军  王小琴  乔禹欣  祖永平 《大豆科学》2017,36(3)

采用室内生理检测及生物化学方法,研究了青霉菌发酵液对大豆幼苗生长及生理特性的影响。结果表明:用一定浓度的青霉菌发酵液对大豆浸种和茎叶处理,大豆幼苗的生长呈明显上升趋势,处理后大豆的株高、根长、株鲜重和根鲜重均明显得到了提高,且生长状态好于对照,不同浓度处理间具有明显差异,在发酵液浓度为5 g·L-1时,效果最佳。尤其是对根鲜重的影响,促进率最高可达56.21%,同时增强了幼苗根系活力,最大可以提高57.82%,浸种和茎叶处理后,分别提高了叶绿素含量41.25%和15.40%;超氧化物歧化酶活性12.20%和11.70%;过氧化物酶31.33%和29.95%;过氧化氢酶活性42.8%和20.0%,这为发酵液在大豆田推广应用、提高大豆产量提供了重要理论依据。  相似文献   

miR-140-3p inhibits viability,invasion and migration of non-small-cell lung cancer A549 cells by targeting PD-L1     

ZHANG Yu-xuan  LI Chun-wei  MAO Wen-hao  ZHU Ke-yan  SHAO Yang-qian  DENG Xiao-ming 《园艺学报》2019,35(1):8-14

AIM: To explore the target relationship between microRNA-140-3p (miR-140-3p) and programmed cell death ligand 1 (PD-L1) and their effect on the viability, migration and invasion of non-small-cell lung cancer A549 cells.METHODS: RT-qPCR was used to detect the miR-140-3p expression in HLF-1, A549 and H1299 cells, and then the A549 cells with the most significant difference were selected as the subsequent research object. TargetScan software and dual-luciferase reporter assay were performed to predict and confirm the target relationship between miR-140-3p and PD-L1. RT-qPCR and Western blot were used to determine the effects of miR-140-3p mimic and inhibitor on PD-L1 expression level. MTT assay was used to detect the viability of A549 cells. Transwell assay was performed to detect the migration and invasion abilities of the A549 cells.RESULTS: miR-140-3p was significantly down-regulated in the A549 cells and H1299 cells (P<0.05). Transfection with miR-140-3p mimic decreased the expression of PD-L1 and inhibited the viability, migration and invasion of the A549 cells. Transfection with pcDNA3.0-PD-L1 reversed the inhibitory effect of miR-140-3p on the viability, migration and invasion of the A549 cells.CONCLUSION: miR-140-3p inhibits the viability, migration and invasion of A549 cells by targeting PD-L1.  相似文献   

Residue Depletion Study and Withdrawal Period for Cefalonium Intramammary Infusion (Dry cow) in Bovine Milk     

YAN ChaoQun  LI ShuaiPeng  ZHANG Shen  XIE Shun  WEI KaiYun  HUANG XianHui 《中国农业科学》2019,52(2):367-375

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Mapping the spatial distribution of shade provision of street trees in Boston using Google Street View panoramas     

《Urban Forestry & Urban Greening》2018

Street trees provide shade and increase human thermal comfort during hot summer. In this study, we investigated the spatial distribution of shade provision of street trees in Boston, Massachusetts. The sky view factor (SVF), which influences the solar radiation to the ground and affects human thermal comfort, was used to indicate the contribution of street trees on shade provision. Google Street View (GSV) panoramas were used to calculate the photographic method based SVF (SVF_P), with the consideration of all kinds of obstructions within street canyons. A building height model was used to calculate the simulation based SVF (SVFs), with consideration of obstruction of building blocks only. Considering the fact that street trees and building blocks are the two major obstructions of radiation within street canyons, therefore, the difference between the two SVF estimation results can be considered as the shade provision of street trees. The results show that street trees help to decrease the SVF by 24.61% in Boston, Massachusetts. The shading level varies spatially in the study area. Generally, the southwestern area has much higher shading level than the north and the east. We further explored the shading variation among different socioeconomic groups in the study area. Result shows that Hispanics tend to live in neighborhoods with lower shading level. This study can help to provide a reference for future urban greening projects for global climate change adaption.  相似文献   

果蔬型甜玉米新品种京科甜191的选育     

徐丽  樊艳丽  卢柏山  席胜利  张翠芬  高宁  董会  刘焱辉  史亚兴 《中国蔬菜》2018,1(10):76-78

京科甜191是以超甜玉米自交系T68为母本,自交系T6302为父本,通过杂交选育而成的果蔬型甜玉米品种。果穗筒型,穗长19.0 cm,穗粗5.3 cm,穗行数16~18行,行粒数36~38粒,粒行整齐。籽粒亮黄色,外观漂亮。平均每667 m2鲜果穗产量900 kg左右,出籽率约67.4%。鲜籽粒含粗蛋白2.98%,粗脂肪1.37%,总糖6.7%,口感甜脆清爽,皮薄无渣。播种至采收平均85.4 d(天),适宜京津冀及类似生态区种植。  相似文献   

FoxA2 and p53 regulate the transcription of HSD17B1 in ovarian granulosa cells of pigs     

Xiaolong Yuan  Xiaofeng Zhou  Xiwu Qiao  Qi Wu  Zhixiang Yao  Yao Jiang  Hao Zhang  Zhe Zhang  Xilong Wang  Jiaqi Li 《Reproduction in domestic animals》2021,56(1):74-82

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养猪场沼渣制备包膜缓释肥理化性质表征     

刘筱  黄彬  胡林潮  毛林强  张文艺 《中国沼气》2020,(1):85-90

文章以分散式养猪场沼渣为应用研究对象,以8%聚乙烯醇为包膜材料,改性斜发沸石为肥料载体和缓控释材料调理剂,通过添加不同沸石量制备3种复混包膜缓释肥。利用红外光谱、扫描电镜及三维荧光对3种缓释肥的进行表征。结果表明:添加改性沸石的复混包膜肥除了增加显著的沸石红外特征谱外,其余红外光谱图差异不明显,表明添加沸石对有机质(富里酸和腐殖酸)结构和化学键型并未产生明显的影响,即不影响沼渣理化性质;添加改性沸石可以使聚乙烯醇完整的覆盖在肥料表面,膜壳更加平整光滑,膜层更加致密;三维荧光光谱显示复混包膜肥Ⅰ浸出富里酸和腐殖酸浓度最大,复混包膜肥Ⅲ浓度最低,表明添加沸石有减缓肥料养分释放的效果。该研究对于利用养猪场沼渣制备包膜缓释肥有一定的参考价值。  相似文献