油菜素甾醇对沟叶结缕草长期培养愈伤组织生长和再生的影响

为了维持长期培养植物愈伤组组织的高再生率,以应用于体细胞无性系进行变异筛选.本研究以继代15年的沟叶结缕草[Zoysia matrella(L.)Merr.]胚性愈伤组织为材料,用不同浓度的表油菜素内酯(EBL)处理,研究油菜素甾醇(BR)对其生长和再生的影响,选出可提高长期离体培养愈伤组织生长及再生效率的最优EBL浓...     

苦荞粒形相关性状的遗传分析

利用籽粒大小差异较大的2个苦荞品种的杂交后代开展了与产量具有密切关系的粒形相关性状的遗传规律及其性状间的相关性分析。结果表明,F₂和F₃群体的粒长、粒宽、长宽比和千粒重表现值范围都超过亲本的表现值,并且粒长、粒宽和长宽比的变异系数均小于10%,千粒重的变异系数大于10%。另外,粒长、粒宽、长宽比和千粒重的加性方差均大于显性方差,广义遗传率在F₂和F₃代中分别为0.77~0.82和0.82~0.85,固定遗传率都达到0.80以上。粒形性状间的相关性分析结果表明,粒长、粒宽和千粒重相互间都存在极显著的正相关,粒宽和千粒重,粒长和长宽比的遗传相关系数较大。以上结果表明,具有较高遗传率的粒形相关性状可以在后代早期进行选择,但由于这些性状是数量性状而且受多个基因的控制,因此建议继续繁殖后代到基因型稳定,同时考虑性状间的相关性选拔最为有效。     

新疆红花地方种种子含油率与主要农艺性状间的灰色关联分析

为了新疆红花地方种高油品种的选育和改良提供科学数据,本研究采用灰色关联分析法,在新疆农业科学院综合试验场对来自新疆的51份红花材料的种子含油率与主要农艺性状进行分析。结果表明,新疆红花地方种的种子含油率与12个主要农艺性状的关联顺序为单株果球数>株高>三级有效分枝数>顶果球着粒数>节间长度>皮壳率>千粒重>生育期>一级有效分枝数>二级有效分枝数>分枝总数>节间数,表明单株果球数、株高、三级有效分枝数是影响新疆红花地方种种子含油率的重要因素。因此,在新疆红花地方种培育高油品种时,应优先考虑单株果球数,株高和三级有效分枝数等指标。本研究结果为培育高油红花提供科学参考数据。     

晋中盆地典型耕地厚度、土壤养分空间变异

旨在探究旱作区耕地土壤耕层厚度及土壤养分空间格局与变异规律。以晋中盆地典型耕地土壤为研究对象,运用地统计学方法对耕地耕层厚度及土壤养分的空间变异进行分析,土壤养分选取有机质、pH、有效磷、缓效钾4个指标。结果表明：（1）各个指标的空间自相关性都是随着距离的增加而减小;（2）有效磷的半变异函数最优模型为高斯模型,其他指标的最优模型均为指数模型。各指标的块金系数由大到小依次为：有机质>有效磷>pH>耕层厚度>缓效钾;（3）耕层厚度、有效磷均为西北高东南低的空间格局,缓效钾为东北高西南低,有机质为西南高东北低,pH除北洸乡偏低外均偏高。地统计方法能良好地描述土壤性质的空间分布和变异特征,各土壤性质的空间变异过程中随机性与结构性并存,并且随机性均小于50%。     

新乡贤队伍建设与乡村振兴:来自绍兴的调查与研究

作为"乡贤研究会"首创之地和"新乡贤"概念诞生之地,绍兴市自然也是新乡贤队伍建设的先行之地,已经成为全国乡贤文化之乡和新乡贤队伍建设的标杆。绍兴市的新乡贤队伍建设,肇始于2001年上虞乡贤研究会的成立,在2015年的乡贤政策年臻于高峰。经过多年培育和发展,定位为"村民自治的有益补充"、起"补位和辅助作用"的近2万新乡贤队伍,在乡村经济、文化、公益、自治等方面发挥着积极作用,但与此同时也显现了新乡贤队伍建设流于形式、结构相对失衡,以及党政介入过度、党政机构与新乡贤组织职责和权力边界不清晰等问题。解剖这一领先全国的典型个案,对于其他地区的新乡贤队伍建设和现代乡村振兴,无疑具有较好的理论意义和现实价值。     

Predicting the potential geographic distribution of Bactrocera bryoniae and Bactrocera neohumeralis(Diptera: Tephritidae) in China using MaxEnt ecological niche modeling

Bactrocera bryoniae and Bactrocera neohumeralis are highly destructive and major biosecurity/quarantine pests of fruit and vegetable in the tropical and subtropical regions in the South Pacific and Australia. Although these pests have not established in China, precautions must be taken due to their highly destructive nature. Thus, we predicted the potential geographic distribution of B. bryoniae and B. neohumeralis across the world and in particular China by ecological niche modeling of the Maximum Entropy(Max Ent) model with the occurrence records of these two species. Bactrocera bryoniae and B. neohumeralis exhibit similar potential geographic distribution ranges across the world and in China, and each species was predicted to be able to distribute to over 20% of the globe. Globally, the potential geographic distribution ranges for these two fruit fly species included southern Asia, the central and the southeast coast of Africa, southern North America, northern and central South America, and Australia. While within China, most of the southern Yangtze River area was found suitable for these species. Notably, southern China was considered to have the highest risk of B. bryoniae and B. neohumeralis invasions. Our study identifies the regions at high risk for potential establishment of B. bryoniae and B. neohumeralis in the world and in particular China, and informs the development of inspection and biosecurity/quarantine measures to prevent and control their invasions.     

Deep neural network algorithm for estimating maize biomass based on simulated Sentinel 2A vegetation indices and leaf area index

Accurate estimation of biomass is necessary for evaluating crop growth and predicting crop yield.Biomass is also a key trait in increasing grain yield by crop breeding.The aims of this study were(i)to identify the best vegetation indices for estimating maize biomass,(ii)to investigate the relationship between biomass and leaf area index(LAI)at several growth stages,and(iii)to evaluate a biomass model using measured vegetation indices or simulated vegetation indices of Sentinel 2A and LAI using a deep neural network(DNN)algorithm.The results showed that biomass was associated with all vegetation indices.The three-band water index(TBWI)was the best vegetation index for estimating biomass and the corresponding R2,RMSE,and RRMSE were 0.76,2.84 t ha−1,and 38.22%respectively.LAI was highly correlated with biomass(R2=0.89,RMSE=2.27 t ha−1,and RRMSE=30.55%).Estimated biomass based on 15 hyperspectral vegetation indices was in a high agreement with measured biomass using the DNN algorithm(R2=0.83,RMSE=1.96 t ha−1,and RRMSE=26.43%).Biomass estimation accuracy was further increased when LAI was combined with the 15 vegetation indices(R2=0.91,RMSE=1.49 t ha−1,and RRMSE=20.05%).Relationships between the hyperspectral vegetation indices and biomass differed from relationships between simulated Sentinel 2A vegetation indices and biomass.Biomass estimation from the hyperspectral vegetation indices was more accurate than that from the simulated Sentinel 2A vegetation indices(R2=0.87,RMSE=1.84 t ha−1,and RRMSE=24.76%).The DNN algorithm was effective in improving the estimation accuracy of biomass.It provides a guideline for estimating biomass of maize using remote sensing technology and the DNN algorithm in this region.     

棉铃虫棉田自然种群变化动态及对天敌观察研究初报

棉铃虫在上世纪80~90年代,在我国多个老棉区严重发生或大暴发,致使棉花生产造成了严重损失。而后棉区迁移至新疆,加上抗虫棉的推广、综合治理措施的落实,有效遏制了棉铃虫的猖獗发生。近几年,在冀南多种作物上又有抬头,并有逐年加重的趋势,为对棉铃虫发生规律研究提出了新课题。     

接骨木无性系苗期干旱胁迫响应及抗旱性综合评价

为揭示不同种接骨木无性系的抗旱性,探讨其对干旱环境的适应能力,为干旱瘠薄山地造林提供材料。采用盆栽法进行自然干旱胁迫试验,运用主成分分析对不同处理下各无性系生理指标进行综合评价。结果表明：干旱胁迫下,无性系PT-1的生物量增量最大,PT-2的根冠比最大。在干旱胁迫逐增情况下,细胞膜透性逐增,当干旱达到中、重度时,无性系PT-1和PT-2的细胞膜透性最小。叶绿素含量及超氧化物岐化酶活性均随干旱程度增加呈先增后降趋势。随干旱胁迫增加可溶性糖和脯氨酸均随之增大。在重度干旱胁迫下,无性系PT-1的可溶性糖含量最大。主成分分析得出,各无性系抗旱能力由强到弱为：XY-2、JY-1、XY-1、XY-3、PT-1、PT-3、PT-2。其中,XY-2、JY-1具有较强抗旱性,可初步作为抗旱材料进行后续研究。