国家区试鲜食夏大豆品种重要农艺性状的演变

为指导鲜食夏大豆高产优质新品种的选育与推广,分析了2006-2018年国家区试鲜食夏大豆13年的品种试验数据,研究了鲜食夏大豆品种14个重要农艺性状的演变规律。研究结果表明:2006-2018年8个鲜食夏大豆新品种通过国家审定;14个农艺性状的变异范围在6.75%～38.67%之间,A级口感率的变异系数最大,标准二粒荚宽最小;参试品种的平均鲜荚产量为10 468.9 kg·hm^-2,较对照减产1.7%;随着年度的推进,鲜荚产量得到了提升,采青天数、株高、主茎节数、单株有效分枝数、单株有效鲜荚数有下降趋势,而多粒荚率、单株鲜荚重有上升趋势,百粒鲜重、标准二粒荚长和宽、标准荚率、A级口感率逐步提升。相关性分析表明,鲜荚产量与多粒荚率、单株鲜荚重、百粒鲜重、标准二粒荚长和宽、标准荚率极显著正相关,A级口感率与百粒鲜重、标准二粒荚长和宽极显著正相关。主成分分析表明,影响鲜食夏大豆性状变异的最主要因子是标准二粒荚长和宽、荚数、多粒荚率及株型因子,在鲜食夏大豆选育过程中应注重选择多粒荚多、荚长、荚大、粒大的品种进行组配,以提高鲜食夏大豆的产量和品质。     

亚麻进化与近缘种研究回顾与展望

本文对亚麻近缘种收集、分类、进化以及分子技术的应用等方面的研究进行了回顾,并指出有必要对中国亚麻属植物进行系统的研究。     

The Cuban homegarden ‘conuco’: a perspective environment for evolution and in situ conservation of plant genetic resources

Summary Cuban homegardens are called conucos. On the basis of new case studies additional information is provided about these conucos, their history, composition and importance. They and other gardens of similar type are characterized as suitable environment for in situ conservation and for the continuation of evolutionary processes.     

Variation among Spanish faba beans cultivars: taxonomic and evolutionary implications

Summary Univariate and multivariate analysis were used to examine phenotypic variability within a Spanish faba bean germplasm collection maintained at the Centro de Investigación y Desarrollo Agrario, Córdoba, Spain.The analysis of 158 Spanish faba bean accessions and 12 quantitative traits indicated highly significant differences among botanical groups for 8 characters and among geographic regions for 10 characters. An east to west clinal pattern of variation for some characters was detected.In order to identify the main characters which account for the major variation, the same collection was subjected to principal component analysis for 12 quantitative traits. Reproductive and plant height characters appeared to be the major sources of diversity.To determine the importance of both geographic and botanical variation among the Spanish cultivars, discriminant analysis was applied. According to these analyses, plant height, height of the lowest pod-bearing node, pod length and 100 seed weight, were important traits discriminating among different geographic regions. The main character discriminating among botanical groups was the 100 seed weight.Our results fit in a pattern in which both agroecological and anthropological causes could have played a role in the observed variation. This analysis can help plant breeders in choosing the most favorable accessions in plant breeding.     

Phases of soil erosion-derived colluviation in the loess hills of South Germany

In South Germany, soil erosion is as old as farming and dates back to Early Neolithic times. Its sedimentary products form thick colluvial and alluvial sediment bodies in all drainage basins. Numerous local studies exist but the extrapolation of findings from local case studies to a regional scale has been problematic. Here, a graphical approach is used for frequency analysis of existing data. A frequency distribution for optical dates on colluvial sediments from the beginning of agriculture until 1200 AD was constructed by: (1) representing the optical ages by Gaussian-distributions and (2) summing all the single curves. The resulting graph clearly shows phases of increased colluviation during periods of stronger human impact. A first significant increase occurred during the Bronze Age. During the Iron Age/Roman period and at around 800 AD, distinct maxima appear in the distribution, and highest frequencies are present towards the end of the analysed period at around 1100 AD. Conclusions that can be drawn from such an approach are limited by sampling bias and other factors, but for the analysed period, and on a regional and long-term scale, colluviation seems to have been mainly triggered by intensity of land use. Climatic fluctuations are of only secondary importance. Rainfall events that were sufficiently erosive to produce colluvial sediments occurred throughout the agricultural periods. The limiting factor for colluvium production was sensitivity of the landscape to erosion, and this is a result of land use.     

长江中下游近10年冬小麦区试主要农艺性状演变分析

利用2012—2021年间国家小麦区域试验长江中下游组212份参试品系的主要农艺性状区试结果,分析其近10年的演变规律。结果表明,该区域小麦产量和穗粒数先减后增、有效穗数明显减少、千粒重和株高不断增加、生育期基本保持平稳。今后,长江中下游麦区产量应当在保持现有产量结构的基础上,注意提高千粒重,适当降低穗粒数,培育早熟品种为主,更有利于该麦区产量提升。     

基于非期望产出的河北省耕地生态效率时空演变及收敛性分析

为探究河北省耕地生态效率内在提升机制以及实现耕地经济、社会、生态综合效益最大化,以河北省137个县域为单元,利用非期望SBM模型测度2000—2017年河北省县域耕地生态效率,并从省、市、县层次分析耕地生态效率的时空特征,运用空间自相关探寻空间作用关系,采用收敛模型进行了收敛分析。结果表明:(1)从省、市角度来看,河北省耕地生态效率在研究期内大致呈现先下降后上升的趋势,即由0.773下降到0.563,再上升到0.796,效率水平还有待提高。(2)从县域来看,整体上各县耕地生态效率水平有所提升,但处于无效状态的县域单元较多,占总单元的89.1%,并且在空间上存在一定的聚集效应。(3)从收敛性情况来看,河北省全省和北部、中部的耕地生态效率整体上均存在不稳定的σ收敛,而南部不存在σ收敛。同时河北省耕地生态效率存在绝对β收敛,主要体现在北部、中部、南部之间,其内部不存在绝对β收敛。河北省耕地生态效率尚存较大提升空间,北部、中部、南部区域内部各县耕地生态效率差异正逐步扩大,区域内各县未来应加强合作,促进区域各县农业协调发展。     

陕西省耕地压力时空演变及驱动因素研究

在复杂的国际形势和新冠病毒为社会带来严峻考验的背景下,我国的粮食安全问题显得更为重要。陕西省是西北地区农业生产的重要基地,探索分析其耕地压力时空演变特征与驱动因素,对区域耕地资源有效利用与粮食安全保障有重要意义。基于陕西省1995—2019年耕地数量和分布情况,对最小人均耕地面积Smin与耕地压力指数P进行测算,对传统差异指数进行整合,建立总体分异测度指数GDI,引用重心移动模型和总体分异测度指数GDI描述区域内耕地压力的时空变化特征,并借用灰色关联分析法对耕地压力变动的驱动因素进行分析与探讨。结果表明：1995—2019年陕西省耕地面积总体呈先下降后上升的趋势;耕地压力指数整体呈下降趋势,但变化幅度较小,仍长期处在“警戒压力”水平;陕西省耕地压力重心在关中地区,先向北偏西移动,之后逐年向南推移;陕西省耕地压力空间分异情况2003年之前不明显,且状态相对平稳,2003年之后分化格局日趋明显;1995—2019年无霜期情况、降水情况、粮食单产量、化肥使用、农村居民收入、城镇居民收入、经济发展水平、工业水平对陕西省耕地压力存在不同程度的影响作用。     

海岛棉GH9基因家族成员鉴定及分析

植物GH9基因在细胞壁的生物合成和重塑中起着重要作用,对海岛棉GH9基因进行全基因组鉴定与分析,挖掘其在棉纤维发育中的作用。从海岛棉全基因组中鉴定到53个GH9基因,分析其理化性质、基因结构、染色体分布、进化历程、棉纤维发育过程中表达模式及转录调控。结果表明,53个GbGH9s分为A、B、C三组,定位在22条染色体上;多倍化事件是海岛棉GH9基因家族扩张的主要驱动力,基因复制后经历严格的选择约束;A组多个成员在棉纤维发育整个时期尤其是次生壁加厚期高表达,C组多个成员在棉纤维起始和伸长期优势表达,B组具有相对复杂的表达模式,生长素和乙烯可能在GbGH9s的转录调控中发挥重要作用。此外,通过回交将GbGH9B6导入陆地棉可提高棉纤维强度。海岛棉GH9基因家族成员的鉴定及分析有助于明确其进化和功能,为后续研究提供重要参考。     

昆明城区公共绿地时空演变特征研究

以昆明中心城区2010、2015和2019年遥感影像目视解译后公共绿地信息数据为研究对象,从整体尺度、行政区域和环形单元等方面,用数理统计与空间分析法相结合,对公共绿地空间演变特征进行分析。结果表明:昆明中心城区公共绿地在2010—2019年期间呈现持续增长的趋势,呈贡区公共绿地面积增长速度最快,盘龙区面积增长速度较慢,其他三个单元增长速度保持中速;环形单元中一、二、三环区域公共绿地增长速度较缓慢,四环公共绿地面积增长明显。