基于GIS与RS的北方防沙屏障带生态系统格局演变

研究北方防沙屏障带生态系统格局演变特征,对加强屏障带建设、改善生态环境具有重要意义。以北方防沙屏障带为研究区,根据2005、2010、2015年MODIS遥感影像,将北方防沙屏障带生态系统类型划分为森林、草地、湿地、农田、城镇、荒漠和裸地7类。采用空间统计、转移矩阵、景观指数分析法、PNTIL模型等方法,对北方防沙屏障带2005—2015年生态系统类型时空演变特征进行分析。结果表明,2005—2015年北方防沙屏障带生态系统整体呈稳定状态;从分屏障带看,内蒙古防沙屏障带荒漠面积明显减少,塔里木防沙屏障带森林面积迅速增加,而河西走廊防沙屏障带草地面积明显增加;从正/逆转换方向来看,屏障带内农田、城镇、荒漠及裸地生态系统正向转换率高于逆向转换率。10年间,在景观水平上,北方防沙屏障带斑块数量、斑块密度呈减少趋势;在类型水平上荒漠景观整体呈现破碎化萎缩的趋势特征,森林、草地向形状简单化的方向发展。研究表明,2005—2015年,北方防沙屏障带生态总体向好,治沙效果明显,但局部仍面临较大压力。     

Whitened kernel surface: A fast and reliable method for assessing Fusarium severity on cereal grains by digital picture analysis

Fusarium head blight (FHB) is a cereal disease of major importance responsible for yield losses and mycotoxin contaminations in grains. Here, we introduce a new measurement approach to quantify FHB severity on grains based on the evaluation of the whitened kernel surface (WKS) using digital image analysis. The applicability of WKS was assessed on two bread wheat and one triticale grain sample sets (265 samples). Pearson correlation coefficients between Fusarium‐damaged kernels (FDK) and WKS range from r = 0.77 to r = 0.81 and from r = 0.61 to r = 0.86 for the correlation between deoxynivalenol (DON) content and WKS. This new scoring method facilitates fast and reliable assessment of the resistance to kernel infection and shows significant correlation with mycotoxin content. WKS can be automated and does not suffer from the “human factor” inherent to visual scorings. As a low‐cost and fast approach, this method appears particularly attractive for breeding and genetic analysis of FHB resistance where typically large numbers of experimental lines need to be evaluated, and for which WKS is suggested as an alternative to visual FDK scorings.     

考虑土壤水平衡的灌区水资源优化配置研究

针对内蒙古河套灌区解放闸灌域地下水埋深较浅且矿化度高及黄河水量逐年减少等因素导致的农业用水严重短缺问题,本研究以解放闸灌域玉米为研究对象,耦合Jensen模型与土壤水平衡模型构建灌区尺度灌溉水资源优化配置模型,对不同的地下水埋深及土壤含水量情景下水资源优化配置方案进行研究,并利用Lingo软件编程求解模型。结果表明:当地下水埋深为2.5m时,引黄水量为3.85×10~8 m~3,可以达到5.55×10~8元的净经济效益;而土壤水含量为0.12～0.16时,净经济效益为[5.41,5.67]×108元。优化结果验证了模型在当地可行,并针对河套灌区解放闸灌域的不同土壤含水量与地下水埋深情景分别提供14种配水方案。     

盐胁迫对羽衣甘蓝种子萌发的影响

为探明盐胁迫对羽衣甘蓝种子萌发特性的影响，明确种子萌发期对盐胁迫的耐受能力，本试验以羽衣甘蓝种子为试验材料，研究不同浓度的NaCL（0、40、80、120、160、200mmol/l）和NaHCO（3 0、20、30、40、50、60mmol/l）对种子萌发胁迫的作用。结果表明:1、2 种盐胁迫处理下，羽衣甘蓝种子的发芽率、发芽势、发芽指数和活力指数等指标均随着盐浓度的升高逐渐降低；2、高浓度的NaHCO³盐溶液对羽衣甘蓝种子的胚根、胚芽的生长抑制较NaCL 盐溶液显著；3、2 种盐     

茶足柄瘤蚜茧蜂脂代谢相关的滞育关联基因差异表达分析

本文对茶足柄瘤蚜茧蜂滞育组与正常发育组进行转录组测序，筛选差异表达基因，根据功能注释发现这些滞育关联基因主要与碳水化合物代谢、脂质代谢以及信号转导等途径相关。借助KEGG数据库，共筛选出滞育期间401个与脂代谢相关的差异基因，在滞育期间呈现不同程度的上调表达，涉及了脂肪酸生物合成、甘油脂代谢、类固醇生物合成等代谢途径，除与脂质合成相关的脂肪酸合成酶、超长链脂肪酸延伸酶基因上调表达外，与脂质分解相关的酶，如酯酶同样上调表达，可能与提高茶足柄瘤蚜茧蜂免疫力有关；与激素合成相关基因的上调表达，可能抑制茶足柄瘤蚜茧蜂卵巢发育。     

杂交旱稻丰产节水栽培关键技术研究与集成应用

针对安徽沿淮地区气候特点,通过试验筛选出适宜沿淮地区旱种旱管栽培,丰产性和稳产性较好的旱稻品种5个,节水耐旱型水稻品种7个;明确了沿淮地区以旱优73为代表的杂交旱稻的丰产节水栽培技术:播种期6月5-12日,播种量2.0 kg/667 m~2左右,氮肥用量10~14 kg/667 m~2;在施肥过程中适当降低基蘖肥用量、增施穗粒肥,基、蘖、穗肥比例以4∶4∶2较好。     

Verrucosamide,a Cytotoxic 1,4-Thiazepane-Containing Thiodepsipeptide from a Marine-Derived Actinomycete

A new cytotoxic thiodepsipeptide, verrucosamide (1), was isolated along with the known, related cyclic peptide thiocoraline, from the extract of a marine-derived actinomycete, a Verrucosispora sp., our strain CNX-026. The new peptide, which is composed of two rare seven-membered 1,4-thiazepane rings, was elucidated by a combination of spectral methods and the absolute configuration was determined by a single X-ray diffraction study. Verrucosamide (1) showed moderate cytotoxicity and selectivity in the NCI 60 cell line bioassay. The most susceptible cell lines were MDA-MB-468 breast carcinoma with an LD₅₀ of 1.26 µM, and COLO 205 colon adenocarcinoma with an LD₅₀ of 1.4 µM. Also isolated along with verrucosamide were three small 3-hydroxy(alkoxy)-quinaldic acid derivatives that appear to be products of the same biosynthetic pathway.     

不同种植方式对甜菜产质量的影响

试验结果表明,在同等条件下,由于栽培方式不同,密度不同,块根产量、产糖量差异较大,以纸筒大垄双行为最好,甜菜块根产量、产糖量比对照小垄直播分别提高36.7%、39.8%,每公顷纯增效益1602元。其次是大垄双行覆膜,块根产量、产糖量比对照小垄直播分别提高31.5%、33.1%。