京郊休闲型家庭农场发展创新策略及保障机制

北京郊区具备发展休闲型家庭农场的多种条件,可以通过理性规划,准确定位;注入农耕文化,融于体验;塑造品牌,注重营销的创新发展策略来展开。在此基础上,政府应通过加强引导,提供各种政策保障;调整发展思路,促进农场区域化发展;建立休闲型农场专门人才的培养机制,提升农场主文化与经营水平等一系列保障机制来实现。     

8个格木天然林种源苗期生长差异与早期选择

为研究格木不同天然种源家系苗的生长差异,选出相对速生的优良种源,本研究对8个格木天然林种源、110个家系1年生的苗高和地径等生长量指标进行测量,结合各家系的种子表型性状进行方差分析、多重比较、相关性分析和聚类分析。结果表明:不同种源的格木苗期生长量差异显著,具备种源选择的基础;不同种源的苗期生长量差异主要来源于种源内,具备从优良种源内选择优良家系的基础;苗期生长量与种子大小、种子厚和千粒重等性状呈极显著正相关关系,大粒、饱满种子可作为优良种源和家系选择的初选参考指标。初步选出浦北、北流种源作为格木优良种源。本研究为格木速生种源及家系的早期选择提供依据。     

玉米XYLPs基因家族表达模式及其蛋白结构分析

通过生物信息学的方法对玉米木质形成素类阿拉伯半乳糖蛋白(xylogen-like arabinogalactan proteins,XYLPs)基因家族的表达模式和蛋白结构进行了分析。ZmXYLPs基因家族成员在染色体上的分布具有一定的偏好性。基因复制事件不仅在基因家族成员数量的扩张和进化中发挥重要作用,同时还可能引起基因表达部位的扩张。根据ZmXYLPs蛋白结构特点,可将其分为两大类。其中仅ZmXYLP10/13/14蛋白存在N连接的糖修饰位点,其余ZmXYLPs蛋白均为O连接糖修饰位点。结果显示,玉米ZmXYLPs的生物学功能可能与其糖基侧链有关,并且其作用并不局限于维管组织发生过程,可能也参与生殖发育过程。     

东晋南朝庐江何氏家学与家风述论

东晋南朝庐江何氏家族是安徽地域境内传统文化世家，在注重文化传家的成长道路上，形成了具有自身品格的家学与家风。庐江何氏家学实践以佛教文化、玄学、儒学为主要内容，不同时期各有侧重，终呈现综合交融的趋势，其家学之影响在与主流文化的互动中得以彰显。庐江何氏家风以“清身洁己”为外在特征，在长期的家学实践中不断丰富自身内涵，何氏家风为其文化型士族成长、争取社会政治利益起到了重要的潜在作用。     

基于家族基因分析的甘蓝MLPK互作PUB蛋白的筛选

MLPK(M–位点受体激酶)是芸薹属自交不亲和正向调控关键元件,其参与自交不亲和信号传导的分子机制尚不明确,同时自交不亲和下游信号元件也有待于进一步分离。为了探索分离MLPK互作蛋白的思路和方法,构建了不含核定位信号的MLPK短截蛋白(MLPK-T),并利用酵母双杂交检测到MLPK与臂重复蛋白1(ARC1)作用,通过全基因组鉴定分别获得了96个甘蓝、101个白菜、70个琴叶拟南芥和62个拟南芥PUB蛋白,其中含有臂重复序列的PUB蛋白共为127个。通过系统进化分析,筛选到8个含臂重复序列的甘蓝BoPUB蛋白,其8个基因全部在柱头内表达,且成功利用酵母双杂交检测到MLPK与3个含臂重复序列的BoPUB蛋白Bol008579、Bol016165和Bol023511相互作用。     

利用MAS技术改良香稻‘R15’的直链淀粉含量

R15是适应性较广,产量较高的中熟晚籼香稻品系,但由于含有Wx^a基因,其直链淀粉含量高达23.5%,严重影响食用口感。因此,我们以含有Wx^b等位基因的不育系Y58S为供体,通过杂交、回交,利用RAD测序技术、分子标记辅助筛选等技术,经过8个世代的筛选,成功用Wx^b基因替换掉R15中的Wx^a基因,培育出1个新的纯合株系——‘深华R16’,其染色体上有10882234 bp长度的碱基,基因型和供体亲本‘Y58S’一致,占2.92%;有362363285 bp长度的DNA片段基因型和受体亲本‘R15’一致,占97.08%;其直链淀粉含量为14%。将‘Y58S’分别与‘深华R16’和‘R15’进行组配,结果表明,‘Y58S’/‘深华R16’组合的直链淀粉含量(13.9%)低于‘Y58S’/‘R15’组合的直链淀粉含量(19.9%),其它米质性状与农艺性状基本一致。本研究为分子标记辅助育种提供了新思路,培育出一新的水稻品系。     

土地规模化经营能否促进农业社会化服务获取?——基于全国3类农户样本的实证分析

土地流转和农业社会化服务是经营规模化和服务规模化的根本途径,研究二者关系对农业供给侧结构性改革、农业现代化发展乃至乡村振兴具有重要意义。基于第二期"全国新型农业经营主体发展指数调查"数据,运用负二项回归模型实证分析土地流转及转入不同特征土地对普通农户、专业大户和家庭农场农业社会化服务获取的影响。结果表明,单纯的土地转入对不同类型农户农业社会化服务获取均不具有显著影响。但如果转入土地有利于规模化经营、农业基础设施较好,则能显著促进社会化服务获取。另外,农户经营能力越强,对不同类型社会化服务的应用程度也越高。因此,政府应推动更有效率的土地流转,实现农业适度规模经营;加强农业社会化服务供给,提升农户生产经营效率;强化经营主体培训,增强联结带动能力。     

Simultaneous selection for seed and forage production in cocksfoot (Dactylis glomerata): application of drought tolerance and susceptibility indices

An experiment was conducted to estimate drought tolerance of some cocksfoot genotypes based on seed and forage yield and related indices (including tolerance index, mean productivity, geometric mean productivity, reduction percentage index, stress tolerance index and stress susceptibility index) and to identify relationships between measured traits. Twenty‐five genotypes were evaluated in the field under control and drought‐stress environments over 2 years. The results revealed a high variation for seed yield and forage yield and the measured indices under both moisture conditions. No correlation was observed between seed yield and forage yield under the control treatment, but this correlation was positively significant under the water‐stress treatment. Drought‐tolerant and susceptible genotypes were identified based on seed and forage yield performance. Genotypes 2, 4 and 7 had high seed yield, while genotypes 7 and 10 had high forage yield under both stressed and non‐stressed conditions and were identified as the most tolerant genotypes in each category. The results also revealed that genotypes 1, 2, 4, 6, 7, 8 and 24 had relatively high seed and forage yield in both control and drought‐stressed conditions. These genotypes can be used for further studies to improve both seed and forage yields concurrently.     

Identification of genotyping-by-sequencing sequence tags associated with milling performance and end-use quality traits in hard red spring wheat (Triticum aestivum L.)

Genotyping-by-sequencing (GBS) utilizes Next-Generation sequencing to genetically and physically map traits of interest. Here we use GBS to identify QTLs and SNP markers associated with milling and end-use quality traits in an hard red spring wheat recombinant inbred line (RIL) population. The RIL population and parents were phenotyped for eleven milling and end-use quality traits, and genotyped using GBS technology, simple sequence repeat (SSR) and allele specific sequence tagged site markers. A genetic map comprising 696 markers was used to map the end-use quality traits. Multiple QTL mapping identified 79 QTLs, 19 of which were declared ‘major’ as they explained greater than 15% of the phenotypic variance each. Transgressive segregants were observed for all phenotypes and co-locating QTLs controlling multiple quality traits were confirmed on chromosomes 1BL, 5AS, 7AS, 7AL and 7BS. To date, no GBS analysis to locate end-use quality QTLs in wheat has been conducted, thus the reporting and validation of these GBS sequence tags and their associated QTLs will shed light on the genetic architecture underlying these quantitative traits and assist wheat breeders in developing cultivars with favorable alleles through the use of marker assisted selection.     

Interactive effects of family and stocking density on survival and growth of the sea urchin Strongylocentrotus intermedius

To investigate the effects of family, stocking density, and their interaction on mortality, growth rate, and size dispersal in the sea urchin Strongylocentrotus intermedius, 1,440 juveniles from six full‐sib families were exposed to three stocking densities, that is, low stocking density (LD), middle stocking density (MD), and high stocking density (HD), and reared for 10 months in sea‐based suspended cages. The results demonstrated significant family effects on cumulative mortality rate (CMR); specific growth rate for test diameter (SGR for TD); specific growth rate for body weight (SGR for BW); coefficient of variation for body weight at the 10th month (CV for BW₁₀); and significant stocking density effects on SGR for TD, SGR for BW, and CV for BW₁₀. Statistically significant family by stocking density interaction was only found in SGR for TD. A certain degree of family‐ranking inversions occurred in SGR for TD. The present study provides evidence for the existence of family by stocking density interaction on the growth rate of test diameter in the family selection for S. intermedius. More attention should be paid to this interaction effect to select correct parents in S. intermedius.