Optimizing the application of a novel harvest aid to improve the quality of mechanically harvested cotton in the North China Plain

Defoliation is an indispensable step in cotton production with mechanical harvesting, especially in the North China Plain (NCP) where mechanical harvesting is limited by a large proportion of green leaves and unopened bolls at harvest time due to insufficient thermal resources. It is essential to quantify the optimal use of defoliation products while minimizing yield and quality loss in China. The objective of this study was to test the effect of a new defoliant Xinsaili (XSL, a compound of 10% thidiazuron and 40% ethephon) on the spatial distribution of cotton leaves and bolls, yield and quality in the NCP. There were four treatments: XSL 1800 mL ha^–1, XSL 2700 mL ha^–1, XSL splitted into two equal applications (1350 mL ha^–1 for each), and XSL-free (water) control. Field experiments were conducted in Hebei, China in 2016–2017. All the defoliant treatments did not significantly affect cotton yield and fiber quality compared with the water control. At harvest time, the rate of open bolls under XSL 2700 mL ha^–1 was 13.5% higher than that under XSL-free control, while the other two treatments showed no significant difference, across the two years. Defoliation percentage of the three XSL treatments showed no difference, but they were on average 42.2% higher than that of XSL-free control. The year-round effect of the defoliant XSL was significant, indicating that climate factors would affect its application. It was concluded that the optimal dose of XSL in the NCP was 2700 mL ha^–1, and it was unnecessary to split it into two applications. These results would promote cotton mechanical harvesting and reduce the labor cost of cotton production in China.     

油菜毯状苗适宜移栽密度研究

为探讨油菜毯状苗移栽的适宜密度,采用田间试验,以甘蓝型油菜品种宁杂1818为材料,研究了毯状苗不同移栽密度对油菜籽粒产量、品质及单株干物质积累的影响。结果表明,油菜产量与密度间呈二次抛物线关系,随密度增加呈现先增加后降低的趋势。移栽密度为22.5万株/hm^2时,一穴一株处理(CK)产量最高,为3806.81 kg/hm^2,一穴两株处理(M4)产量略低于CK,二者差异不显著,但M4处理显著高于其它处理。随密度增加,单株角果数和每角粒数减少,而群体角果数增多。单株产量与成熟期和蕾臺-初花期的干物质积累量间呈现极显著正相关关系。随密度增加,油菜籽粒含油量小幅度增大,蛋白质、硫苷和芥酸含量降低。以最高产量下降1%以内为标准得出适宜的移栽密度范围为22.75万~28.39万株/hm^2,而且生产上油菜毯状苗移栽时可灵活采用一穴两株或一穴一株,简化、高产、高效。     

森林草莓转录因子MYB 12基因克隆及蛋白特性分析

采集森林草莓(Fragaria vesca)植株叶片,TRIzol法提取样本总RNA,设计特异性引物RT-PCR扩增转录因子MYB 12基因,获得1条约1 kb大小的特异性片段,克隆并测序。序列分析表明,该片段序列全长988 nts,含有完整的MYB 12基因开放阅读框(ORF),ORF长度为855 nts,编码285个氨基酸。序列比对发现,森林草莓MYB 12基因与来源于5种蔷薇科植物MYB基因的序列相似性较高,为75%~76%,而与其他7种非蔷薇科植物MYB基因的序列相似性相对较低,为47%~68%。构建MYB基因系统关系树,发现森林草莓与其他5种蔷薇科植物的MYB基因聚成一个分支,说明森林草莓与蔷薇科植物亲缘关系较近。生物信息学分析表明,MYB 12蛋白具有一定的亲水性,其N-端有2个MYB结构域,属于R2R3-MYB亚族。MYB 12蛋白二级结构主要以α-螺旋为主,并含有一些不规则的卷曲(Random coil)结构。这为研究该基因在植物生长发育及生理代谢过程中的调控机制奠定了基础。     

土壤渐进干旱过程中玉米、高粱茎水分传输能力与光合作用的协调性研究

以两种不同抗旱性的玉米品种("陕单21"和"郑单958")和高粱品种("晋中405"和"晋杂12")为对象, 研究了土壤渐进干旱过程中茎木质部水分传输能力与光合作用之间的协调关系, 试图揭示玉米和高粱品种抗旱性差异的水力生理机制。结果表明: (1)相同土壤干旱程度下, 玉米品种"郑单958"的叶水势、净光合速率(Pn)、最大光化学量子效率(Fv/Fm)和PSⅡ实际量子效率(ΦPSⅡ)高于"陕单21", 其气孔导度(Gs)及蒸腾速率(Tr)则低于"陕单21"。高粱品种"晋杂12"的Pn和ΦPSⅡ高于"晋中405"。表明玉米品种"郑单958"和高粱品种"晋杂12"的抗旱性相对较强。(2)土壤渐进干旱过程中, 玉米和高粱光合气体交换参数(Pn、Gs及Tr)的下降早于叶绿素荧光参数(Fv/Fm、ΦPSⅡ)的下降, 表明气孔关闭比PSⅡ活性受损要早。(3)抗旱性强的玉米品种"郑单958"和高粱品种"晋杂12"同时具有相对高的水分传输能力, 其抵抗气穴化形成的能力更强, 但高粱抵抗气穴化的能力不如玉米, 高粱通过快速的栓塞来减少水分散失。(4)玉米Pn和Gs对茎木质部水分传输能力下降的敏感性高于高粱, 抗旱性强的玉米和高粱品种Gs对木质部水分传输能力下降的敏感性更强。高粱能在低水分传输能力的情况下, 维持较高的光合作用, 反映了高粱保守性的水分利用策略。     

Molecular mechanism underlining ethanol-induced chloride currents in nasopharyngeal carcinoma cells

AIM：To study the effects and mechanisms of ethanol on chloride channels in poorly differentiated nasopharyngeal carcinoma CNE-2Z cells. METHODS：The effect of ethanol on the cell growth was analyzed by MTT assay. The technique of whole-cell patch-clamp was used to detect the chloride current. The characteristics of the chloride current were analyzed by using the chloride channel blockers. The siRNA technique was used to analyze the molecular basis of the ethanol-sensitive chloride channels. RESULTS：Under isotonic conditions, the background current was weak and stable. Ethanol at concentrations of 0.17~170 mmol/L activated a chloride current in a concentration-dependent manner (an inverted U-shape), with a maximum effect at the concentration of 17 mmol/L. The currents showed obviously outward rectification and were susceptible to extracellular hypertonicity and the chloride channel blocker, 5-nitro-2-(3-phenylpropylamino) benzoic acid (NPPB). ClC-3 siRNA obviously decreased the currents activated by ethanol. CONCLUSION：Extracellular ethanol induces chloride currents through activating the ClC-3 chloride channels.     

美国薄壳山核桃引种幼龄期生态适应性的初步研究

对5个美国薄壳山核桃引种吉泰盆地的物候期进行观测,并连续两年对其成活率、保存率与形态指标生长量及虫害防治情况进行调查.结果表明：①不同核桃品种之间的物候期存在差异,芽萌动期极差值最大,其次为芽开裂期、展叶期;物候期最早的是赣选4号,最晚的则是赣选5号;②赣选2号、4号成活率与保存率较高,赣选2号与4号的树高增长最快,赣选1号树高增长较慢;而地径增长当年不同品种的差异不显著,翌年的差异显著;冠幅面积年均增长量表现为赣选4号＞赣选5号＞赣选2号＞赣选3号＞赣选1;③综合比较初步认为赣选4号与赣选2号较适宜在泰和引种栽培.     

Design of PID control algorithm on large diameter tiled-grating

To realize the long-time dynamic stability for the tiled-grating control system,a PID algorithm based on the analysis of the four-dimensional degree of freedom mathematical model for the tiled-grating is developed. Two improvements are made in incremental PID algorithm. The latches compensation method is used to avoid saturated loss,and the four-point center difference method is applied to avoid interference. The splicing spot photos of the tiled-grating’s closed-loop control experiments demonstrate that the tiled-grating which employs the improved PID algorithm can acquire a long-time stability as well as the stability can keep one hour.     

3种种植模式下牧草生产性能的比较

皇竹草(Pennisetum hydridum)、甜高粱(Sorghum bicolor)、扁穗牛鞭草(Hemarthia compessa)是重庆市3种主推牧草,合理地搭配种植这3种牧草能为重庆地区提供更好的四季青绿饲草,并获得生物量和营养成份的高产。本研究设定了3种不同的种植面积比例组合模式（3∶1∶1、1∶2∶1和1∶1∶1）,通过测定3种种植模式下牧草组合的干草产量及主要养分,最终筛选出适合重庆地区养牛的最佳牧草种植模式。结果表明,皇竹草、甜高粱、扁穗牛鞭草种植面积为3∶1∶1时,牧草干物质、粗蛋白、粗脂肪、粗纤维、无氮浸出物、Ca和P的总产量较高,分别达到20 366.09、1 677.38、620.15、6 851.76、9 442.87、237.97和128.86 kg·hm-2。本研究筛选的重庆地区最佳的养牛种草模式为皇竹草∶甜高粱∶扁穗牛鞭草种植面积为3∶1∶1,此模式能获得较高的干草产量和养分含量。     

新疆桑树资源利用及桑树产业“生态-经济一体化”发展思路

桑树是新疆维吾尔自治区古老的树种之一,新疆的桑树资源分布广泛且极具特色。通过查阅历史文献和实地考察等方式,对新疆桑树资源在民间文化习俗、维吾尔医药、生态防护、蚕丝生产及保健食品开发等方面的应用历史与现状进行调研分析,并初步提出以新疆桑树资源为物质基础,打造具有生态、经济、文化特点的新疆桑树产业模式,实现"生态-经济一体化"发展的思路,以期通过桑树资源的多元化开发利用,发展新疆的桑树产业。     

油菜杂交种和亲本胚的增重特性差异

通过Richards方程模拟不同品种油菜胚干重的动态变化,结果表明:正反交杂交种(系)前期经历的天数、积累的干重以及所占总生育期、总积累量的比例都小于父母本,而中期和后期都高于父母本,从而延长了杂交品种生育期的天数,增加胚干重;杂交品种最大速率、各期平均速率和整个积累过程的平均速率均小于常规品种.