推进种养结合的制约因素及政策建议

随着粮食增产的迫切需求和化肥工业的快速发展,我国种植业与养殖业养分物质循环断裂,推进种养结合成为实现农业绿色发展重要途径。但目前,我国从农户层面以及区域层面都存在着种植与养殖之间的纽带断裂,造成了农业资源利用的错位,也产生了资源环境双重压力。推进种养结合的堵点主要表现在养殖场责任尚未压实、有机肥施用不便利、堆肥质量标准缺失、社会化服务体系不完善等多方面。本文结合对国内和国际上推进种养结合的典型做法的分析,在强化提升国家粮食安全保障能力的大背景下,从优化种养布局规划、压实养殖主体责任、强化科技支撑、培育社会化服务组织等方面提出了当前构建全新的种养循环体系的建议。     

高产奶牛孕检后同期发情程序选择的研究

为了研究适用于高产奶牛的同期发情程序方案,将218头膘情良好、子宫和卵巢发育正常的不同胎次荷斯坦牛随机分成两组,试验1组为106头,试验2组为112头,分别采用两种同期程序(0.5.6.8和0.7.8.9)进行处理,测定情期受胎率,用于评价两种同期程序对高产奶牛的适用性。结果表明,试验2组情期受胎率平均为41.96%,显著高于试验1组的平均情期受胎率30.19%(P<0.01);将参与试验的218头牛根据胎次分成1胎组、2胎组和3胎及以上组,分析不同胎次对输精效果的影响,2胎情期受胎率最高为40.68%,与1胎情期受胎率存在显著差异(P<0.05),3胎及以上的情期受胎率最低为28.79%,与2胎、1胎存在极差异显著(P<0.01)。     

达里诺尔湖湿地生态系统服务价值评价

生态系统服务功能是生态系统与生态过程所形成及所维持的人类赖以生存的自然环境条件与效用,对其服务价值进行货币化评价,可以推动自然资源可持续利用,促进区域生态环境保护。以达里诺尔湖湿地为研究对象,结合达里诺尔湖湿地生态系统的结构、特征及其生态过程特点,通过资料搜集与实地调研,运用资源经济学理论和方法,对达里诺尔湖湿地生态系统服务价值进行了划分。构建了达里诺尔湖湿地生态系统服务价值评价指标体系,并对其进行了价值评价。评价结果显示达里诺尔湖湿地的服务价值为93.70×10⁴万元,其中直接使用价值为2.19×10⁴万元,占比为2.36%,间接使用价值为91.51×10⁴万元,占比为97.66%。各项生态系统服务功能中以调节空气湿度价值最大,为82.76×10⁴万元,占总服务价值的88.32%。     

不同地表覆盖方式对胡杨幼苗光合特性的影响及评价

为筛选对胡杨幼苗生长有效的地表覆盖物。以1年生胡杨幼苗为试材,设置覆膜(T1)、覆草苫子(T2)、覆沙(T3)和裸地(CK)共4种处理,利用相关性分析和隶属函数值法全面评价3种地表覆盖物对植株产生的效果。结果表明:T1、T2、T3处理均显著提高了不同月份的土壤含水率(P<0.05),平均土壤含水率较CK分别提高了26.1%、27.9%和23.5%;各覆盖均显著提高了成活率、株高及地径的生长,T2增长幅度最大;各覆盖均显著提高了叶片净光合速率(P n)、气孔导度(G s)、蒸腾速率(T r)(P<0.05),生长初期T1值最大,生长中后期T2值最大;T2处理的最大净光合速率(P max)、光饱和点(L SP)最大,光补偿点(L CP)和暗呼吸速率(R d)最低;各覆盖对水分利用效率(W UE)和表观量子效率(A QY)影响较小;植株生长与土壤含水率、P n、G s、P max、L SP呈极显著正相关(P<0.01),综合效果由强到弱顺序为T2、T3、T1、CK。覆草苫子较适宜在胡杨幼苗栽植过程中应用推广。     

An efficient method to produce segregating populations in quinoa (Chenopodium quinoa)

Quinoa offers a promising alternative for staple food, considering its outstanding nutritional value and tolerance to abiotic stresses. To develop breeding programmes in quinoa, a reliable crossing method for increasing the genetic variation is required. In the following study, we aimed to develop segregating populations in quinoa. We tested the efficiency of three different crossing methods (hand emasculation, warm water emasculation and no emasculation). Moreover we developed a two-stage selection strategy based on morphological traits and molecular markers for the selection of hybrid plants. We reported hand emasculation to be the most efficient crossing method, followed by warm water emasculation and no emasculation. Our results demonstrated that crosses in quinoa can be successfully performed, despite its complicated flower structure and high self-pollination rate. Additionally, we developed 30 segregating populations from crosses between accessions of different origins with varying phylogenetic relationship, which offers a promising perspective for quinoa breeding programmes in the future.     

Maize defence mechanisms against the European corn borer,Ostrinia nubilalis Hübner (Lepidoptera: Crambidae)

Maize is arguably the most widely grown crop in the world, but it is often associated with one of its major insect pests, the European corn borer (ECB). The damage caused by this species to maize production is generally variable, but in many cases it is economically significant. This review paper provides an overview of the research findings on the natural plant defence mechanisms against ECB larvae published till now. What is resistance and how it is achieved, what is the chemical response of maize plants to insect feeding and how tolerance can be increased. A short introduction in breeding for resistance and a discussion if the mentioned traits can be used in conventional breeding in order to create maize hybrids less affected by ECB are given.     

Identification and verification of quantitative trait loci for eating and cooking quality of rice (Oryza sativa)

This study was conducted to identify new quantitative trait loci (QTLs) that have stable effects for eating and cooking quality (ECQ) of rice. Three recombinant inbred line populations of indica rice were each planted in two years. Three traits for ECQ, amylose content (AC), gel consistency (GC) and alkali spreading value (ASV), were measured for QTL analysis. A total of 13 QTLs were detected, including four for AC, six for ASV and three for GC. Two QTLs, qGC4 in the interval RM16252–RM335 on the short arm of chromosome 4 and qGC6.2 in the Alk region, were validated in a population derived from a residual heterozygote that was homozygous at the major locus Wx. In the absence of segregation at the Wx locus, qGC4 and qGC6.2 had additive effects of 2.46 and 8.18 mm, respectively, offering a potential for improving GC property of rice varieties. Comparison between qGC4 and previous results suggests that qGC4 is likely a new QTL for GC, providing a candidate for gene cloning and functional characterization.     

Screening oat germplasm for better adaptation to cold stress in the Southern Great Plains of the United States

Oat (Avena sativa L.) is one of the most important forage crops in the Southern Great Plains of the United States. However, it is more sensitive to cold stress than other small grains. In this study, diverse oat germplasm was evaluated for winter survival across multiple years and locations in the region. Field screening started with an observation trial of 1,861 diverse genotypes in the 2012–2013 season and was followed by four seasons of replicated trials from 2013 to 2017. Selection of good winter survivors was started in 2014–2015 season. All trials were laid out in randomized complete blocks with replications of two in 2013–2014 and 2014–2015, four in 2015–2016, and three in 2016–2017. Winter survival was scored in a 1‐to‐9 scale. Data were analysed for each year and location separately. Additive main effects and multiplicative interaction (AMMI) analysis were carried out on combined data of 35 genotypes that were commonly grown in each year and location. Highly significant (p < 0.001) variations were observed among genotypes, environments and genotype‐by‐environment interaction (GEI). The first three interaction principal components (IPCs) were highly significant (p < 0.001), explaining 96% of GEI. Broad sense heritability ranged from 46% to 93%, while heritability for all environments combined was relatively low (24.6%). At the end of the two cycles (2014/2015‐to‐2016/2017) of selection, mean winter survival was improved by more than 38% per cycle compared with the base population mean. Genotypes CIav 4390, CIav 6909 and CIav 7618 showed significantly higher winter survival than the standard checks Okay and Dallas. Genotypes CIav 4390 showed 20% and 35% improvement over the standard checks Okay and Dallas, respectively. Winter survival improvement in oat will remain a difficult task because of high GEI and low heritability. The identified superior genotypes will be used as crossing parents to transfer cold tolerance genes to other elite lines.     

Agronomic performance of winter wheat grown under highly divergent soil moisture conditions in rainfed and water‐managed environments

Even in the temperate climates of Europe, increasing early season drought and rising air temperature are presenting new challenges to farmers and wheat breeders. Sixteen winter wheat (Triticum aestivum L.) genotypes consisting of three hybrids, six line cultivars and two breeding lines from Germany as well as five line cultivars from France, Austria, Slovakia, Hungary and the Ukraine (referred to as “exotic” lines) have been included in this study. The genetic materials were evaluated over three growing seasons under a range of soil moisture regimes at the three North German sites Braunschweig (irrigated and drought‐stressed), Warmse (rainfed) and Söllingen (rainfed). The average grain yields in the twelve growth environments (water regime × season combinations) ranged from 6.1 to 13.5 t ha^?1. The exotic lines showed little evidence of specific phenological adaptation to drought although they are frequently faced with water scarcity in their countries of origin. The hybrids and German lines exhibited higher regression coefficients (b_i) to environmental means than the exotic lines, indicating particular adaptation to favourable growing conditions. The phenotypical correlations of grain yield between the various environments were high, ranging for instance from 0.6 to 0.8 for the irrigated and drought‐stressed environments at Braunschweig. It is thus expected that in the foreseeable future continued selection aiming at high yield potential will suffice as a means to counter the expected increase in droughts.     

泰州市稻田综合种养产业发展分析及建议

系统阐述了泰州市稻田综合种养产业的发展现状,包括分布区域、经营主体、种养模式等,统计了不同种养模式的应用面积、产量及收益,对稻田综合种养及常规稻麦种植两种模式下的经济效益进行了对比。结果表明,稻田综合种养模式能显著提高土地利用率,促进当地农业增效和农民增收。通过对稻田综合种养模式推广应用过程中的比较优势以及存在问题进行系统分析,提出了针对性的解决措施和建议。