基于一年期物候监测的珠穆朗玛峰国家级自然保护区河谷阶地青稞地块生态利用研究

在当前生态文明建设和乡村振兴战略大背景下,村域土地的生态利用显得格外重要。以珠穆朗玛峰自然保护区西部吉隆县境内Z村感兴趣区(ROI)青稞地块为研究区,通过Brinno TLC 200物候相机以人工选点、定角安放的方式记录研究区2017年8月至2018年8月的一年期土地利用变化信息,计算绿叶指数,分析研究区土地利用规律、土地利用程度、植被覆盖变化及经济效益。结果表明,2017年8月至2018年8月研究区土地利用分为5个月的耕种期和7个月的放牧期。其中,耕种活动集中在4—9月,牧牛期为9、12月和次年1月,牧羊期为12月—次年4月。研究区土地利用程度的高、中、低级别分别对应耕种期、放牧期和休耕期。全年不同时期植被覆盖变化较大,绿叶指数呈现出平缓波动—上升—下降—平缓波动的规律,与青稞地块利用时间历的耕种和放牧期变化相吻合。绿叶指数在0值附近波动时,牛、野生动物和羊出现,降水频繁;绿叶指数为正值时,劳动力投入量大。青稞地块的经济效益为98.15元·(667 m~2)~(-1),以粮食收益为主,劳动力投入费用较高,总体经济效益偏低。     

Differences in the quality of steamed hull-less barley and wheat cakes北大核心CSCD

In this study, three different hull-less barley varieties were used to prepare steamed cakes, and their nutritional value, sensory qualities, textural properties, and in vitro starch hydrolysis were evaluated. The results showed that the contents of total dietary fiber (4.50%-5.12%), β-glucan (2.96%-3.96%), total flavonoids (12.56-38.73 mg/100 g), and γ-aminobutyric acid (5.08-9.53 mg/100 g) in the steamed hull-less barley cakes were significantly higher than that in the steamed wheat cake, which were 0.65%, 0.23%, 3.93 mg/(100 g), and 2.63 mg/(100 g), respectively. The sensory properties of steamed ordinary hull-less barley and wheat cakes were not significantly different, but the steamed 08-1127 (waxy hull-less barley) cake was softer and out of shape. The springiness, resilience, cohesiveness, gumminess, and adhesiveness of steamed ordinary hull-less barley cakes were similar to those of steamed wheat cake, while those of steamed 08-1127 cakes were significantly lower than those of steamed ordinary hull-less barley cakes. Steamed hull-less barley cake also showed a maximum starch hydrolysis rate (38.76%-42.74%) that was lower than that of steamed wheat cake (49.92%), and the contents of rapidly (11.58%-13.16%) and slowly digested starch (5.34%-7.56%) were lower than that of steamed wheat cake (17.21% and 15.97%, respectively). In addition, the glycemic (59.37-61.67) and hydrolysis indexes (35.82-40.00) were lower than those of steamed wheat cake (76.66 and 67.30, respectively), and the contents of resistant starch (2.74%-3.55%) were higher than those of wheat steamed cake (1.68%). Therefore, the steamed cakes of ordinary hull-less barley had a higher content of nutritional components than the steamed cake of wheat, and the in vitro starch hydrolysis parameters were better than those of steamed wheat cake. When it is necessary to consider both nutritional and sensory qualities, ordinary hull-less barley can be selected as the raw material for steamed cakes, but waxy hull-less barley is not suitable for making steamed cakes. © 2022 Science Press. All rights reserved.     

青稞β-1,3-葡聚糖酶II基因启动子的克隆分析及表达载体的构建

根据本实验室克隆并公布的藏青稞β-1,3-葡聚糖酶II(BGH II)基因序列,以藏青稞QB09基因组DNA为模板,构建DNA步移文库,并通过步移技术克隆出BGH II起始密码子上游调控序列BGHP. 鉴定和分析表明,BGHP具备大多数高等植物启动子的保守元件,预测它对BGH II基因的表达具有一定的作用.为鉴定BGH II基因的基本启动子元件,将基因5′侧翼序列做缺失片段分析,利用PCR方法从BGHP中得到3个不同大小两端带有Hind Ⅲ、BamHⅠ酶切位点的片段BGHP1、BGHP2和BGHP3,定向插入载体pMGFP4(pBI221改建,报告基因为GFP)中,取代原有的CaMV35S启动子,构建了由驱动报告基因GFP的植物表达载体BGHPV1、BGHPV2和BGHPV3,用于大麦的遗传转化,为进一步研究其功能奠定了基础. 图5 表1 参15     

青藏高原青稞B组醇溶蛋白遗传多样性研究

报道了青藏高原青稞B组醇溶蛋白的遗传多样性.在66份青藏高原青稞材料中,共有15种不同条带、29种不同条带组合,表明青藏高原青稞材料具有丰富的多态性.不同来源的群体材料间遗传多态性存在差异,西藏育成品种的多态性略低于四川农家品种,人工选择使其遗传多态性减弱.聚类分析将材料分成3组,材料聚类与材料来源地没有明显的相关性.图3表5参26     

2010-2019年西藏粮食增产的贡献因素北大核心CSCD

粮食安全关系到西藏农牧民的生计与社会稳定.为促进粮食产量提高,以西藏自治区7个地级行政区为生产单元,采用2010-2019年粮食作物的播种面积、产量等数据,运用迪氏指数法定量分析10年来各行政区粮食产量变化差异,探讨粮食增产的主要因素.结果表明:(1)近10年来西藏粮食增长趋势较为明显,增幅达15.9%;(2)日喀则是西藏的主要粮食产区,对粮食增产的贡献率最大,为42.2%;(3)近年来的产业结构调整进一步突出了青稞的重要位置,增加了青稞的播种面积,青稞对粮食产量的贡献率达到76.6%;(4)从全区来看,对粮食增产的主要贡献因素是作物播种面积增加.因此,近年来西藏主要通过调整种植结构和扩大种植面积获得了增产,而在未来可积极开展复种措施、提高耕地利用系数(如西藏雅鲁藏布江中下游区域)以及通过增加科技投入,如改良品种、推行测土配方、提高农业机械化率等措施来提高作物单产、增加粮食总产.(图2表3参14)