SrUGT76G1对于合成优质甜菊糖苷至关重要，也是目前甜菊中研究最为深入的糖基转移酶基因，但是关于它的转录调控机制目前还不甚了解。本研究通过酵母单杂交手段鉴定得到了一个SrUGT76G1的上游调控因子SrMYB1。SrMYB1属于典型的R2R3类型的MYB类转录因子，其定位在细胞核并且具有转录激活活性。SrMYB1在花中的表达量较高而在叶片中较低。酵母单杂（Y1H）和凝胶阻滞（EMSA）实验证实SrMYB1可以结合在SrUGT76G1启动子的+50～-141区域即F4-3区段。进一步研究发现在烟草表皮细胞和甜菊愈伤组织中SrMYB1均可显著抑制SrUGT76G1的表达。综上所述，本研究不但发现了一个SrUGT76G1的潜在上游调控因子并且丰富了甜菊中糖苷代谢途径的调控网络。

B-box（BBX）基因家族编码的蛋白是由包含锌指结构的转录因子组成，其N端有一个或两个高度保守的B-box基序。BBX蛋白在植物生长发育的各个方面起着至关重要的作用，包括幼苗的光形态发生、避荫、开花时间以及生物和非生物胁迫响应。目前,各国的研究者已经从几种植物中鉴定了BBX的家族成员，然而玉米中的BBX家族成员还知之甚少。通过对玉米BBX家族基因的全基因组鉴定、表达和互作的综合分析，可为了解其功能提供有用信息。本研究共鉴定出36个玉米BBX家族成员，进化分析显示其分布于三个主要分支。在每个主分支中ZmBBXs都具有相似的结构域、基序和基因组结构。基因重复分析表明，玉米BBX蛋白家族的扩张主要是通过片段重复来完成的。利用实时荧光定量PCR技术，本研究分析了ZmBBXs在不同器官组织和不同非生物胁迫条件下的表达。利用生物信息学工具，本研究建立了ZmBBXs蛋白的相互作用网络，并通过双分子荧光互补（BiFC）试验进行了验证。本研究的发现有助于理解ZmBBX家族的复杂性，并为揭示ZmBBX蛋白的生物学功能提供新的线索。

毛花猕猴桃是猕猴桃属中果实抗坏血酸(AsA)含量较高的种之一，但其果实富含抗坏血酸的分子机制尚未被解析。为了深入探明毛花猕猴桃果实富含AsA的分子机制，本研究通过结合基因组学、代谢组学和转录组学构建了AsA代谢相关的调控网络，从而为后续研究奠定基础。在本研究中，我们组装了一个仅含有5个缺口的高质量毛花猕猴桃参考基因组。该基因组由29条染色体组成，大小为615.95 Mb, contig N50为20.35 Mb，其中24条染色体直接来自端粒到端粒。基因组组装评价指标LAI值和QV值分别为21.34%和39.90%，表明组装的基因组已经达到了金标准参考基因组水平。随后，通过代谢组和转录组分析，分别发现61个代谢物和2,092个基因在果实生长发育过程中存在差异积累/表达。在所有的AsA代谢途径中，AsA降解和循环再生途径在整个果实生长发育过程中显著性高表达，表明该途径在AsA调控中起着重要作用。此外，AsA含量与抗坏血酸过氧化物酶基因高度相关。本研究组装的高质量毛花猕猴桃基因组将为毛花猕猴桃遗传育种研究提供坚实的基础，构建的调控网络将为今后毛花猕猴桃的基因功能研究提供公共数据平台。

WOX基因家族是植物特有的一类转录因子，该家族基因在植物生长发育过程发挥重要的功能。本研究在全基因组水平共鉴定到18个苹果WOX家族基因，通过构建系统发育树将这些基因分为三类，保守结构域和基因结构分析得到的分类结果与系统发育结果一致。同线性分析结果表明全基因组复制和片段重复在苹果WOX家族扩张中发挥重要作用。通过实时荧光定量分析，发现苹果WOX基因呈现组织特异性表达，同时MdWOX4a, MdWOX4b, MdWOX5b, MdWOX11/12a和MdWOX11/12b可能在不定根发生过程起到重要的作用。通过转基因烟草不定根发生能力分析，表明过表达MdWOX4b基因显著增强不定根发生能力。以上研究为以后进一步研究MdWOX基因在苹果砧木发育中的功能奠定了基础。

GDSL酯酶/脂肪酶家族包含许多功能基因，它们在植物的生长发育、形态建成、种子油脂合成和防御反应中发挥重要的生物学功能。GDSL酯酶/脂肪酶基因可响应生物和非生物胁迫。虽然GDSL酯酶/脂肪酶家族基因在其他植物中已被鉴定和研究，但它们在番茄中的分类和功能尚不清楚。本研究首次在番茄中鉴定了80个GDSL酯酶/脂肪酶家族基因成员，命名为SlGELP1-80。我们对这些基因在染色体上的位置进行了定位，并对它们的理化性质、基因结构、系统发育关系、共线关系和顺式作用元件进行了分析。SlGELP基因在番茄中的时空表达特征具有多样性。此外，结合RNA-seq分析表明，番茄接种Stemphylium lycopersici前后SlGELP基因的表达模式不同。用qRT-PCR方法验证了番茄接种S. lycopersici病原菌以及分别喷施SA和JA处理后5个显著差异SlGELP基因的表达。本研究首次利用生物信息学方法鉴定和分析了番茄GDSL酯酶/脂肪酶家族基因，为提高植物抗病性研究提供了新的思路。

Argonaute（AGO）蛋白是RNA诱导基因沉默复合体的核心元件，调控植物从器官发育到非生物胁迫的各个过程。AGO基因家族在许多植物中已被鉴定，但在龙眼中并未见报道。此外，AGO如何在植物胚胎的信号通路中对变化的环境刺激作出反应也尚不清楚。本研究对龙眼的AGO基因家族进行了全基因组鉴定，并分析了其在体细胞胚胎发生（SE）、合子胚胎发生（ZE）、组织发育过程、激素反应、光照和非生物胁迫处理的表达模式。结果表明，基于龙眼基因组数据库有10个龙眼AGO基因被鉴定出来，分为4个分支，分布在1、4、8、10、12、13、14和15号染色体上，内含子数目介于2-23个。表达谱分析表明DlAGOs调控龙眼早中期胚胎、种子、花和茎的发育过程。此外，外源激素、光照和非生物胁迫对DlAGOs的转录水平也表现出不同的表达模式。这些研究结果为进一步阐明龙眼EC中RNAi介导的基因沉默机制提供了有用的信息。

黑水虻幼虫（Hermetia illucens）处理畜禽粪便是一种新兴技术，处理产物虫体和虫粪可分别作为动物饲料和有机肥料，然而粪便中残留的重金属会对黑水虻转化过程产生不利影响。本文研究了Cd、Cr、As在黑水虻转化猪粪过程中对黑水虻幼虫生长的影响，以及重金属迁移和形态变化规律。结果表明，As显著降低了黑水虻幼虫的生物量，而Cr和Cd对幼虫的生长无明显影响。黑水虻幼虫对Cd的生物富集系数（BAFs：2.8-3.7）显著高于Cr（0.44-0.62）和As（0.43-0.45）。在黑水虻幼虫转化猪粪过程中，猪粪中的重金属主要迁移到黑水虻的虫粪中，Cd、Cr、As在虫粪中的残留比例分别为52.6-62.0%、90.3-94.2%和93.0-93.3%。转化后，虫粪中Cd含量显著低于猪粪，而Cr和As的含量与猪粪无显著差异（添加150 mg kg^-1 Cr处理除外）。与猪粪相比，虫粪中的重金属形态（弱酸溶解态、可还原态、可氧化态和残留态）均有明显变化。其中虫粪中Cr的可还原态含量降低，但可氧化态比例增加。Cd主要以弱酸溶解态和还原态存在于猪粪和虫粪中。虫粪中As的弱酸溶解态和还原态比例降低。猪粪经过黑水虻转化后，Cr的生物有效性降低了17.3-23.1%， Cd和As的生物有效性无明显变化（CK组的As除外）。这些发现有助于我们了解黑水虻幼虫在畜禽粪便生物转化过程中的作用以及对转化产物的安全利用。

贫困代际传递是全球减贫的核心问题。本研究使用2008年、2012年、2016年和2019年中国5省25个县100个村2000户的追踪调研数据，采用定性和定量方法，通过估计农村非农工资代际传递，研究了中国农村的贫困代际传递问题，并从进入劳动力市场前儿童人力资本投资的角度阐述了贫困的代际传递机制。研究发现，在中国农村地区非农工资存在显著的代际传递，尤其是在父亲非农工资与子女非农工资、父母平均非农工资与子女非农工资之间。但农村非农工资代际传递的弹性远小于城市，表明农村的社会流动性优于城市。父母非农工资高的孩子在进入劳动力市场前，在有可能在接受高等教育、掌握更多技能方面获得更多投资。通过三个案例分析进一步表明，儿童人力资本投资打破了贫困的代际传递，促进了社会流动。

甜菊叶片中的甜菊糖苷由于具有高甜度和低热量的特点而凸显价值，这推动了甜叶菊商业化种植的发展。优化施肥管理可以有效提高甜菊糖苷的生产力，但是目前关于钾肥与甜菊糖苷生产之间的关系尚不明确。本研究通过盆栽试验揭示了甜菊缺钾对叶片甜菊糖苷合成的影响并探索了其潜在机制。结果表明，在高钾土壤背景下，与常规施钾相比，不施钾肥对甜菊生物量没有显著影响。然而，不施钾肥显著降低了叶片中甜菊糖苷的含量以及甜菊糖苷合成相关基因的表达水平。在缺钾条件下，叶片中不同糖组分含量显著降低，糖代谢相关酶的活性受到抑制。此外，通过对甜菊幼苗叶片进行蔗糖喷施可以有效减弱缺钾造成的甜菊糖苷抑制作用。研究结果还揭示了甜菊叶片中蔗糖、葡萄糖与甜菊糖苷含量之间的显著正相关关系。综上所述，我们的研究结果表明缺钾会抑制甜菊叶片中甜菊糖苷合成，而这种抑制作用是由叶片糖代谢介导的。我们的发现为进一步提高甜菊糖苷的生产潜力提供了新的见解。

Received  8 September, 2017    Accepted  13 March, 2018

Migratory insects make diverse adaptive strategies in response to changes in external environment.  Temperature has an impact on the survival, development, reproduction, and migration initiation of insects.  Previous research has primarily been focused on the effects of constant temperature on populations, but changing temperature has received less attention.  Three constant temperature treatments (20, 25 and 30°C) and three pupal-alternating temperature treatments (20–25, 25–20 and 25–30°C) were set up to study the relationship between temperature and population development by age-stage, two-sex life table analysis in the oriental armyworm, Mythimna separata Walker, a notorious migratory pest in grain crops.  The 25°C treatment was considered optimal with 20 and 30°C as low suitable temperature and high temperatures, respectively.  The survival rate was relatively low before third instar larvae at  20°C (63.0%) and 20–25°C (70.1%), and extreme low after pupal stage at 30°C (20.6%).  Developmental duration of each stage was negatively correlated with temperature.  The adult pre-oviposition period, when most migratory insects initiate migration, was the shortest at 25°C (2.69 d) but was lengthened at both low suitable (7.48 d for 20°C, 6.91 d for 25–20°C and 4.57 d for 20–25°C) and high temperatures (3.74 d for 25–30°C and 5.00 d for 30°C).  Both low suitable and high temperature decreased lifetime fecundity, net reproductive rate and the intrinsic rate of increase, with variability observed across developmental duration and stage during non-optimal temperature.  The results expand knowledge of the relationship between changing temperature and armyworm population development, and adaptive strategies in complex ambient environment.

Powdery mildew, caused by Blumeria graminis f. sp. tritici (Bgt), is one of the most damaging diseases to wheat in the world.  The cultivation of resistant varieties of wheat is essential for controlling the powdery mildew epidemic.  Wheat landraces are important resources of resistance to many diseases.  Mapping powdery mildew resistance genes from wheat landraces will promote the development of new varieties with disease resistance.  The Chinese wheat landrace Baiyouyantiao possesses characteristic of disease resistance to powdery mildew.  To identify the resistance gene in this landrace, Baiyouyantiao was crossed with the susceptible cultivar Jingshuang 16 and seedlings of parents and F₁, BC₁, F₂, and F_2:3 were tested with Bgt isolate E09.  The genetic results showed that the resistance of Baiyouyantiao to E09 was controlled by a single recessive gene, tentatively designated PmBYYT.  An Illumina wheat 90K single-nucleotide polymorphism (SNP) array was applied to screen polymorphisms between F₂-resistant and F₂-susceptible DNA bulks for identifying the chromosomal location of PmBYYT.  A high percentage of polymorphic SNPs between the resistant and susceptible DNA bulks was found on chromosome 7B, indicating that PmBYYT may be located on this chromosome.  A genetic linkage map of PmBYYT consisting of two simple sequence repeat markers and eight SNP markers was developed.  The two flanking markers were SNP markers W7BL-8 and W7BL-15, with genetic distances of 3 and 2.9 cM, respectively.  The results of this study demonstrated the rapid characterization of a wheat disease resistance gene and SNP marker development using the 90K SNP assay.  The flanking markers of gene PmBYYT will benefit marker-assisted selection (MAS) and map-based cloning in breeding wheat cultivars with powdery mildew resistance.

Traditionally, Chinese indigenous cattle is geographically widespread.  The present study analyzed based on genome-wide variants to evaluate the genetic background among 157 individuals from four representative indigenous cattle breeds of Hubei Province of China: Yiling yellow cattle (YL), Bashan cattle (BS), Wuling cattle (WL), Zaobei cattle (ZB), and 21 individuals of Qinchuan cattle (QC) from the nearby Shanxi Province of China.  Linkage disequilibrium (LD) analysis showed the LD of YL was the lowest (r2=0.32) when the distance between markers was approximately 2 kb.  Principle component analysis (PCA), and neighbor-joining (NJ)-tree revealed a separation of Yiling yellow cattle from other geographic nearby local cattle breeds.  In PCA plot, the YL and QC groups were segregated as expected; moreover, YL individuals clustered  together more obviously.  In the NJ-tree, the YL group formed an independent branch and BS, WL, ZB groups were mixed.  We then used the FST statistic approach to reveal long-term selection sweep of YL and other 4 cattle breeds.  According to the selective sweep, we identified the unique pathways of YL, associated with production traits.  Based on the results, it can be proposed that YL has its unique genetic characteristics of excellence resource, and it is an indispensable cattle breed in China.   

The importance of nutrient provisions and weaning methods for calves has been well established over the past few years, while as increasing interest has focused on contribution of animal behavior and their overall performance in production regimes.  The present study investigated the effects of feeding methods and space allowance on growth performance, individual and social behaviors in Holstein calves.  Twenty-four Chinese Holstein male and female calves were allocated to either an individual or group of 6 and fed either with a bucket or a teat.  Milk replacer, calf starter, and Chinese wildrye were offered during the experiment.  A fecal index used in the present study was defined as the total fecal scores/total number of calves in each treatment.  The results showed that there was no significant difference among the 4 treatments in terms of feed intake, body weight, average daily gain, and fecal index.  For the feeding behaviors, the ingesting milk time and ingesting milk rate were significantly affected by space allowance, while the feeding methods showed a significant influence on the bunting behavior of the calves.  There was no significant difference among the 4 treatments in terms of licking fixtures, self-grooming, and lying down behaviors, irrespective of the feeding method or space allowance.  However, sucking an empty bucket or the teat was significantly affected by the feeding method.  Several selected group behaviors were examined in the present study, and similar values for sniffing the other calves, social grooming, and cross-sucking behaviors were observed.  Overall, the present study demonstrated that different feeding methods and space allowances had a significant effect on the feeding behavior of calves, while the feed intake, growth performance, health condition, individual and group social behaviors were not significantly influenced.  Furthermore, under intensified production systems, Holstein calves raised in a group may obtain a similar production performance, thus reducing management input and profitability compared with those kept individually.  However, there may be competition during the feeding period.

   Stripe rust, caused by Puccinia striiformis f. sp. tritici, is an important wheat disease in China, seriously threatening wheat production. Understanding the winter survival of the fungus is a key for predicting the spring epidemics of the disease, which determines the crop loss. Estimation of P. striiformis f. sp. tritici winter survival requires processing a large number of samples for sensitive detection of the pathogen in wheat leaf tissue using real-time quantitative reverse transcription PCR (qRT-PCR). A bottleneck for the analysis is the acquisition of a good yield of high quality RNA suitable for qRT-PCR to distinguish dead and alive fungal hyphae inside leaves. Although several methods have been described in the literatures and commercial kits are available for RNA extraction, these methods are mostly too complicated, expensive and inefficient. Thus, we modified three previously reported RNA extraction methods with common and low-cost reagents (LiCl, SDS and NaCl) to solve the problems and selected the best to obtain high quality and quantity RNA for use in qRT-PCR. In the three improved methods, the NaCl method was proven to be the best for extracting RNA from urediniospores of and wheat leaves infected by P. striiformis f. sp. tritici, although the modified LiCl and SDS methods also increased yield of RNA compared to the previous methods. The improved NaCl method has the following advantages: 1) Complete transfer of urediniospores of P. striiformis f. sp. tritici from the mortar and pestle can ensure the initial amount of RNA for the qRT-PCR analysis; 2) the use of low-cost NaCl to replace more expensive Trizol can reduce the cost; 3) the yield and quality of RNA can be increased; 4) the improved method is more suitable for a large number and high quantity of samples from fields. Using the improved NaCl method, the amount of RNA was increased three times from urediniospores of P. striiformis f. sp. tritici compared from the extraction kit. Approximately, 10.11 μg total RNA of high quality was obtained from 100 mg of infected leaves, which was 8.8, 6.5, 3.4 and 2.1 folds of the amounts obtained from the previous LiCl, SDS, NaCl and traditional Trizol methods, respectively. The method could be used to study the overwintering rates of P. striiformis f. sp. tritici over a large region of wheat production for predicting epidemic levels by determining pathogen survival levels after winter. The method can also be used in any studies which need a large number of high quality RNA samples.

A spotted-leaf mutant of rice HM143 was isolated from an EMS-induced IR64 mutant bank. Brown lesions randomly distributed on leaf blades were observed about 3 wk after sowing. The symptom lasted for the whole plant growth duration. Histochemical analysis indicated that cell death occurred in and around the site of necrotic lesions accompanied with accumulation of hydrogen hyperoxide. Agronomic traits were largely similar to the wild type IR64 except seed setting rate and 1 000-grain weight which were significantly decreased in the mutant. Disease resistance of the mutant to multiple races of Xanthomonas oryzae pv. oryzae was significantly enhanced. Genetic analysis showed that the mutation was controlled by a single recessive gene, tentatively termed splHM143. In addition, using molecular markers and 1 023 mutant type individuals from an F2 segregating population derived from the cross HM143/R9308, the spotted-leaf gene was finally delimited to an interval of 149 kb between markers XX25 and ID40 on the long arm of chromosome 4. splHM143 is likely a novel rice spotted-leaf gene since no other similar genes have been identified near the chromosomal region.

Soil organic carbon (SOC) is one of the main carbon reservoirs in the terrestrial ecosystem. It is important to study SOC dynamics and effects of organic carbon amendments in paddy fields because of their vest expansion in south China. A study was carried out to evaluate the relationship between the SOC content and organic carbon input under various organic amendments at a long-term fertilization experiment that was established on a red soil under a double rice cropping system in 1981. The treatments included non-fertilization (CK), nitrogen-phosphorus-potassium fertilization in early rice only (NPK), green manure (Astragalus sinicus L.) in early rice only (OM1), high rate of green manure in early rice only (OM2), combined green manure in early rice and farmyard manure in late rice (OM3), combined green manure in early rice, farmyard manure in late rice and rice straw mulching in winter (OM4), combined green manure in early rice and rice straw mulching in winter (OM5). Our data showed that the SOC content was the highest under OM3 and OM4, followed by OM1, OM2 and OM5, then NPK fertilization, and the lowest under non-fertilization. However, our analyses in SOC stock indicated a significant difference between OM3 (33.9 t ha-1) and OM4 (31.8 t ha-1), but no difference between NPK fertilization (27 t ha-1) and nonfertilization (28.1 t ha-1). There was a significant linear increase in SOC over time for all treatments, and the slop of linear equation was greater in organic manure treatments (0.276-0.344 g kg-1 yr-1) than in chemical fertilizer (0.216 g kg-1 yr-1) and no fertilizer (0.127 g kg-1 yr-1).