贵州碾茶茶园覆网方式浅析

贵州碾茶茶园覆网方式主要有直接覆盖、隧道式覆盖和大棚覆盖3种,其中直接覆盖成本最低,用工最少,操作简单,但容易使蓬面芽叶受损或被灼伤,芽叶产量相对偏低且品质有所下降;大棚覆盖成本最高,用工最多,操作复杂,但蓬面芽叶较完整,受损小,产量较高,芽叶品质有所提高;隧道式覆盖一次性投入比大棚覆盖少,但实际操作时用工较多,芽叶品质则位于前两者之间。     

Control of insect pests using trunk injection in a newly established apple orchard

We evaluated the potential for using preplant trunk injections of emamectin benzoate in nonbearing apple trees. Trees were evaluated for pest injury and emamectin residues throughout the planting season and into the following year. Injections into the trunk best delivered emamectin benzoate to the canopy compared with injections into the taproot, and the higher rate reduced insect pests more than the lower rate. In the following year, differences in insect control between trunk and root injections were less pronounced, but the higher rate of emamectin benzoate persisted longer and better reduced pests relative to the other treatments.     

Protective effect of Huangqi injection combined with puerarin injection on myocardium of type 2 diabetes mice

AIM:To investigate the effect of Huangqi injection combined with puerarin injection on the myocardium of the mice with type 2 diabetes. METHODS:Diabetic KKAy mice were randomly divided into model group and treatment group (Huangqi injection combined with puerarin injection). The male KKAy mice of the same age were used as control group. All mice were sacrificed at 21, 24 and 28 weeks. Morphological changes of the myocardium were observed by HE staining. Apoptosis of the cardiomyocytes was measured by TUNEL staining. The mRNA levels of glucose-regulated protein 78(GRP78), C/EBP hoinologous protein (CHOP) and p53 up-regulated modulator of apoptosis (PUMA) were detected by real-time PCR, and the protein levels of GRP78, CHOP, PUMA, caspase-3, cleaved caspase-3, caspase-9, cleaved caspase-9, poly(ADP-ribose) polymerase (PARP) and cleaved PARP were determined by Western blot. RESULTS:Cardiomyocyte hypertrophy, partly dissolved sarcoplasm and necrosis were observed in model group, and these lesion were alleviated in treatment group. Obvious increased apoptosis in model group and significantly decreased apoptosis of cardiomyocytes in treatment group was observed (P<0.05). At 21, 24 and 28 weeks, the mRNA and protein levels of GRP78, CHOP and PUMA and the protein levels of cleaved caspase-3, cleaved caspase-9 and cleaved PARP in model group were increased significantly as compared with control group (P<0.01), and these in treated group were decreased compared with model group. CONCLUSION:Huangqi injection combined with puerarin injection has cardioprotective effects on type 2 diabetes mice and its mechanism of the action was implemented via inhibiting the activation of endoplasmic reticulum stress and caspase pathway, thus resulting in suppressed apoptosis.     

Wide hybridization and introgression breeding in safflower: Effectiveness of different selection methods

Possibility of using interspecific hybridization to increase genetic diversity of drought tolerance in safflower (Carthamus tinctorius L.) and effectiveness of different selection methods is poorly understood. The main objectives of this study were to evaluate the effectiveness of (a) interspecific hybridization to expand genetic diversity in safflower for agronomic traits and drought tolerance in advance generations and (b) different selection methods (direct vs. indirect) for improving seed yield. Interspecific hybridizations were performed between species of C. tinctorius × C. palaestinus (TP), C. palaestinus × C. oxyacantha (PO) and C. tinctorius × C. oxyacantha (TO). Based on the field screening of genotypes in F3 generation, four groups of selected genotypes (derived from combination of direct and indirect selection under both drought and normal environments along with selection based on drought tolerance index (STI)) were evaluated in F4 and F5 generations. Indirect selection for seed yield was significantly more efficient than direct selection. Selection in stress environment resulted to more efficiency than selection in normal environment. No significant difference was observed between direct selection and selection based on STI. The result showed that TP was the best population to combine high seed yield and drought tolerance in safflower.     

Marker‐assisted breeding for improvement of anaerobic germination in japonica rice (Oryza sativa)

Direct seeding is increasingly being practiced in rice cultivation areas because it saves labour and reduces cost of production and management. In this study, four japonica‐type breeding lines were developed from a cross of a japonica cultivar and an AG‐tolerant donor, KHO, using marker‐assisted selection. Validation of the target genes AG1 and AG2 in the selected lines was examined by PCR analysis and the background recovery rate by the recurrent parent was confirmed by genotyping using a 6K SNP chip. Compared to the recurrent, the survival rates of the selected lines were improved in a range from 33% to 115% in three conditions; in particular, the survival rate was increased in more than twice that of the recurrent parent under the hypoxic condition. The main agronomic trait, yield and quality‐related traits were similar to those of the recurrent parent. The use of these lines will contribute to the expansion of the cultivation area due to the proven economic benefits of direct seeding in Korea.     

高压直流接地极对埋地管道腐蚀的影响和管控思考

高压直流输电、油气长输管道建设促进了全国范围内的能源优化配置,但高压直流接地极放电对埋地管道的强直流干扰问题应该引起足够关注。为进一步加强相关风险管控,回顾中国高压直流输电网的发展历程,对高压直流接地极放电影响管道的典型特点进行分析,结合当前实际提出后续风险管控的发展方向。研究结果表明:邻近油气长输管道路由的高压直流输电线路和接地极对管道的影响具有干扰时间不确定、干扰机理复杂、干扰程度大及缓解困难的特点,是管道当前面临的突出安全风险。高压直流输电网调试或故障运行过程中,接地极单极放电会加速管道腐蚀。后续应从加强沟通协调和联合测试,深化腐蚀机理和规律研究,采取综合治理措施等方面提升检测、研究及治理水平,全方位保障国家能源通道的安全稳定。     

Most fish destined for fishmeal production are food‐grade fish

Marine fisheries target and catch fish both for direct human consumption (DHC) as well as for fishmeal and fish oil, and other products. We derived the fractions used for each for 1950–2010 by fishing country, and thus provide a factual foundation for discussions of the optimal use of fisheries resources. From 1950 to 2010, 27% (~20 million tonnes annually) of globally reconstructed marine fisheries landings were destined for uses other than DHC. Importantly, 90% of fish destined for uses other than DHC are food‐grade or prime food‐grade fish, while fish without a ready market for DHC make up a much smaller proportion. These findings have implications for how we are using fish to feed ourselves or, more appropriately, how we are not using fish to feed ourselves.     

施氮量对油后直播棉花产量、品质及生物量的影响

为研究施氮量对油后直播棉花生物量累积特征及其与产量、品质的关系,于2016-2017年在湖南常德设置了施氮量分别为0、90、180、270、360 kg·hm^-2氮肥水平试验。结果表明,在施氮量为0~360 kg·hm^-2范围内,施氮量越大棉株营养器官生物量累积越多,而棉株生殖器官生物量则在施氮量为270 kg·hm^-2时累积最多;皮棉产量、成铃数和单铃重均在施氮量为270 kg·hm^-2时达到最大;0~270 kg·hm^-2范围内,衣分随施氮量增加而增加。在施氮量为270 kg·hm^-2条件下,纤维长度和断裂比强度最高;适宜施氮量有利于纤维长度、断裂比强度的提高和马克隆值的优化,对伸长率和整齐度基本无影响。综上所述,适宜施氮量可提高棉花的产量、品质,洞庭湖棉区适宜的施氮量为180~250 kg·hm^-2。本研究结果为环洞庭湖棉区的氮肥合理运筹提供了技术参考。     

长江中游稻区水稻产业发展现状、问题与建议

为了解国家调低稻谷保护收购价后长江中游稻区水稻产业发展状况,湖南、湖北、江西和河南4省水稻专家组织开展了相关调研。结果表明,长江中游稻区2018和2019（预测）两年水稻总体种植面积持续缩减,主要是湖南和江西“双改单”和种植结构调整所致,而湖北和河南面积略有增加。稻区内2018年稻谷销售进度明显滞后于上年同期,稻谷价格也不同程度下跌。这主要受国家保护价下调影响。而优质稻谷销售进度和价格受影响较小,其流通表现出更强的市场化。2018年水稻种植人工、地租、化肥和总成本均出现不同程度提高,其中地租和人工成本增加是总成本提高的主要原因。2018年稻米加工企业稻谷收购量、收购价和稻米批发价均不同程度降低。稻区内优质稻和杂交稻种植面积占比均为64%;籼稻面积占比97.6%。不同水稻种植技术应用比例表现为抛秧>手插和直播>机插;再生稻种植面积不断增加,稻渔模式迅猛发展。同时,稻区水稻产业发展面临着农民种粮积极性普遍下降,订单农业发展风险重重,农业基础设施不完善、修缮主体不明确,农业生产社会化程度偏低,稻渔模式无序发展隐患大,农民卖粮难度大、成本高、风险大,区域稻米品牌建设亟待加强等一系列问题。建议政府调整粮食收储政策,加强对农业的政策和补贴支持力度,加强对再生稻和稻渔模式发展的引导,加大科研攻关投入。     

滴度及注射方式对2型腺相关病毒载体表达效果的影响

由于腺相关病毒载体(adeno-associated viral vector,AAV)本身的侵染不具有神经元特异性,其在神经系统相关研究中会存在侵染范围不符合试验要求的情况,因此本试验拟研究不同滴度和注射方式对病毒侵染范围的影响。结果显示,在注射较高滴度的AAV2-CMV-EGFP(1.3×10¹¹mg/L)3周后,其侵染范围可由延髓中缝苍白核(raphe pallidus nucleus,RPa)区域延伸至下丘脑室旁核(paraventricular nucleus,PVN)区域;较低滴度(1.3×10⁸mg/L)结合压力注射的方式可以在一定程度上限制AAV的侵染范围,并且载体携带的EGFP荧光基团在637 nm波段不具有明显的假阳性信号。