对于某些性成熟昆虫（包括褐飞虱）而言，腹部振动（abdominal vibration，AV）是交配过程的启动信号，对成功交配至关重要。目前，关于调控AV的遗传和分子机制的研究很少。我们以往与AV相关的转录组学研究表明，肌抑制肽（myoinhibitory peptide，NlMIP）是调控雌性褐飞虱AV的潜在基因，但其对AV的调控机制尚未报道。本文证实了NlMIP参与调控雌性褐飞虱的AV和交配行为。当NlMIP的敲低效率为59.00%时，雌性褐飞虱在1小时内产生AV的频率和交配成功率分别下降了38.89%和61.11%。此外，6条NlMIP成熟肽也能够调控雌性褐飞虱AV的产生及其交配行为，其中NlMIP2的作用最强。基于系统发育树分析和NlMIP成熟肽能有效激活A家族神经肽G蛋白偶联受体10（A-family neuropeptide GPCR 10，NlA10）的结果表明NlA10是NlMIP的潜在受体。NlA10被敲低后，雌性褐飞虱1小时内产生AV的频率和交配成功率分别下降了28.89%和43.33%。当NlA10被NlMIP2激活时，NlA10偶联到Gαi/q信号通路，从而抑制下游AC/cAMP/PKA，并激活PLC/Ca²⁺/PKC信号通路，进而级联激活MEK1/2介导ERK1/2的磷酸化，最终调控雌性褐飞虱的AV。这些结果为通过干扰雌性褐飞虱的AV进行害虫防治提供了依据。

蔗糖非发酵相关蛋白激酶1（SnRK1）是一类重要的丝氨酸/苏氨酸蛋白激酶，广泛参与了植物的生长发育，并通过代谢及生理过程参与植物对生物与非生物胁迫的应答，同时在植物的碳水化合物分布及糖信号转导中也发挥着重要作用。本研究通过序列比对，从高粱基因组中鉴定到8个SnRK1亚基编码基因，其中3个编码α亚基（SnRK1α1 - SnRK1α3）、3个编码β亚基（SnRK1β1 - SnRK1β3），以及编码γ （SnRK1γ）和βγ（SnRK1βγ）亚基的编码基因各1个。这8个高粱SnRK1基因分布于第1-3、第7、第9等5条染色体，与来自玉米、水稻的SnRK1基因存在共线性，并且这些基因的编码产物在相同亚基上表现出了高度的同源性。基于qRT-PCR的分析结果显示，在8个高粱SnRK1基因中，除SnRK1α3在籽粒中低表达以及SnRK1β2在穗中高表达外，其他基因在其他组织中均表现出相似的表达特性。基于高粱叶片原生质体的亚细胞定位结果表明，α1、α2、α3、γ这4个亚基主要定位于细胞器，而在细胞膜和部分细胞器上则可以检测到β1、β2、β3、及βγ这4个亚基的定位信号。此外，酵母双杂交分析发现，8个高粱SnRK1亚基存在α1-β2-βγ、α2-β3-γ、α3-β3-γ等3种不同的组合模式。这些研究结果，为后续高粱SnRK1亚基的功能解析等研究奠定了良好基础。

 

由核盘菌（Sclerotinia sclerotiorum）引起的豌豆菌核病是我国常见的豌豆病害。然而，我们近期在重庆和四川调查中发现，引起豌豆菌核病的病原菌可有多个核盘菌种。为此，我们对引起重庆和四川豌豆菌核病的病原菌种进行鉴定，以期为病害防控及抗病育种奠定基础。利用常规组织分离方法对采自重庆永川与合川、四川仪陇的病株及菌核进行病原菌分离，对获得的类似核盘菌的真菌分离物用PDA（potato dextrose agar）培养基培养，观察并测量菌落形态、生长速率与菌核大小。利用核糖体基因内转录区（rDNA-ITS）序列和种特异性分子标记进行分离物的分子鉴定。rDNA-ITS序列采用真菌通用引物ITS4/ITS5对分离物基因组DNA进行PCR扩增，种特异性分子标记鉴定分别利用核盘菌、小核盘菌（S. minor）和三叶草核盘菌（S. trifoliorum）特异性引物SMLcc2F/R、SSasprF/R与STCadF/ R对分离物基因组DNA进行PCR扩增，系统发育分析选取10个代表分离物进行ITS序列测序和采用Mega X软件中非加权组平均法（UPGMA）构建系统发育树。致病性测定采用菌丝块接种豌豆植株茎秆方法进行。菌落生长速率和菌核大小差异可将30个分离物区分为“快速生长-中菌核”、“中速生长-小菌核”和“慢速生长-大菌核”3中类型，分别有6个、7个和17个分离物，与已报道的核盘菌属中的核盘菌、小核盘菌和三叶草核盘菌的类似。ITS序列扩增片段将30个分离物分为2个带型，10个代表分离物进一步的系统发育分析表明，2个分离物与小核盘菌（KY550019、MN421822）聚在同一分支，2个分离物与核盘菌（MN216247、MK734068和MF776031）聚在同一分支，6个分离物与三叶草核盘菌（AY187070、AY547267）聚在同一分支。核盘菌种特异性引物扩增结果表明，30个分离物中分别有6、7和17个分离物扩增出小核盘菌、核盘菌和三叶草核盘菌的目标条带。综合形态和分子特征结果，我们确定30个分离物中有6为小核盘菌、7个为核盘菌和17为三叶草核盘菌。致病性测定结果表明，30个分离物对2个豌豆品种均具有致病性，病害症状与田间自然发病症状相似，且从感病植物中分离出病原菌分离物与接种分离物相同。本研究证明重庆市和四川省部分地区的豌豆菌核病有小核盘菌、核盘菌和三叶草核盘菌3种病原菌，其中小核盘菌和三叶草核盘菌引起豌豆菌核病是在我国西南地区首次报道。

由寄生疫霉（Phytophthora parasitica）引起的柑橘根腐病是柑橘生产上普遍发生、对柑橘危害较为严重的一种病害。本研究的目的是建立一种简易快速的结合侧流层析技术判定结果的重组酶聚合酶扩增（lateral flow strip-based recombinase polymerase amplification, LF-RPA）方法检测寄生疫霉，为诊断和防治寄生疫霉引起的柑橘根腐病提供技术支撑。以Ypt1基因为检测的靶标序列，通过多序列比对分析，设计寄生疫霉的特异性引物和探针，建立并优化LF-RPA检测方法，并与简易核酸提取技术相结合，对该检测方法的特异性、灵敏度和实际应用效果进行评估。对LF-RPA体系中的温度、引物和探针比例、时间进行了优化，使得LF-RPA在40°C孵育温度下反应20分钟后即可肉眼判断检测结果。特异性试验中，LF-RPA能特异性地检测出不同来源的寄生疫霉，而其它亲缘关系相近的卵菌病原菌均未检测出。灵敏度试验结果显示，LF-RPA的最低检测灵敏度为1 pg。为了使LF-RPA检测方法更适宜基层使用，对四种不同的简易核酸提取技术进行了比较评估，发现基于PEG-NaOH的简易核酸提取技术更适合本研究。将LF-RPA与PEG-NaOH核酸提取技术相结合，不需要特定的仪器设备，只需要能维持40°C的保温杯，即可在30分钟内完成从发病植株的核酸提取到结果判定的整个检测过程。利用该方法，成功地从接种寄生疫霉的柑橘叶片、枝条和果实上检测出寄生疫霉；此外也从田间采集的10份柑橘发病样品中检测出其中3份样品含有寄生疫霉本研究成功建立了一种针对寄生疫霉的LF-RPA快速检测方法，该方法与简易核酸提取技术相结合，非常适宜于基层使用，为柑橘根腐病的快速诊断奠定了技术基础。

Nitrogen (N) is a critical element for plant growth and productivity that influences photosynthesis and chlorophyll fluorescence. We investigated the effect of low-N stress on leaf photosynthesis and chlorophyll fluorescence characteristics of maize cultivars with difference in tolerance to low N levels. The low-N tolerant cultivar ZH311 and low-N sensitive cultivar XY508 were used as the test materials. A field experiment (with three N levels: N0, 0 kg ha^–1; N1, 150 kg ha^–1; N2, 300 kg ha^–1) in Jiyanyang, Sichuan Province, China, and a hydroponic experiment (with two N levels: CK, 4 mmol L^–1; LN, 0.04 mmol L^–1) in Chengdu, Sichuan Province, China were conducted. Low-N stress significantly decreased chlorophyll content and rapid light response curves of the maximum fluorescence under light (F_m´), fluorescence instable state (F_s), non-photochemical quenching (q_N), the maximum efficiency of PSII photochemistry under dark-adaption (F_v/F_m), potential activity of PSII (F_v/F_o), and actual photochemical efficiency of PSII (ΦPSII) of leaves. Further, it increased the chlorophyll (Chl) a/Chl b values and so on. The light compensation point of ZH311 decreased, while that of XY508 increased. The degree of variation of these indices in low-N tolerant cultivars was lower than that in low-N sensitive cultivars, especially at the seedling stage. Maize could increase Chl a/Chl b, apparent quantum yield and light saturation point to adapt to N stress. Compared to low-N sensitive cultivars, low-N tolerant cultivars maintained a higher net photosynthetic rate and electron transport rate to maintain stronger PSII activity, which further promoted the ability to harvest and transfer light. This might be a photosynthetic mechanism by which low-N tolerant cultivar adapt to low-N stress.

    H9N2 avian influenza virus (AIV) infection is a major problem in poultry industry worldwide. In this study, molecular characterizations and phylogenetic relationships of hemagglutinin (HA) gene sequences of H9N2 AIV of 5 Chinese isolates in 2014 recently available in GenBank, 3 widely used vaccine strains, and 52 novel isolates in China from 2013 to 2015 were analyzed. The homology analysis showed that the nucleotide sequences of HA gene of these recent Chinese H9N2 AIV isolates shared homologies from 94.1 to 99.9%. Phylogenetic analysis showed that all isolates belonged to AIV lineage h9.4.2.5. Fifty-six out of the 57 recent Chinese H9N2 AIV isolates had the motifs PSRSSR↓GLF at the cleavage sites within the HA protein, while one isolate PWH01 harbored LSRSSR↓GLF. Remarkably, all of the recent Chinese H9N2 AIV strains had the Q216L substitution in the receptor binding site, which indicated that they had potential to infect humans. Most of recent Chinese H9N2 AIV isolates lost the potential N-linked glycosylation site at residues 200–202 compared with vaccine strains. This present study demonstrated that AIV lineage h9.4.2.5 was more predominant in China than other lineages as it harbored all the H9N2 AIV isolated between 2013 and 2015. Also we showed the importance of continuous surveillance of emerging H9N2 AIV in China and update of vaccine formulation accordingly in order to prevent and control H9N2 AIV.

Bulk-SSR method was used to analyze the genetic diversity of 44 open-pollinated varieties collected from Henan, Shandong, Shanxi, and Jilin provinces and Guangxi Zhuang Autonomous Region, China using 70 pairs of SSR primers. The purposes of this study were to (1) compare the genetic diversity among 44 Chinese maize open-pollinated varieties; (2) estimate the minimum number of alleles for construction of a stable dendrogram; and (3) trace the genetic relationships among local germplasm from different regions of China. In total, these 70 SSR primers yielded 292 alleles in 176 samples (4×44) analyzed. The number of alleles per locus was 4.17 on average and ranged from 2 to 8. The highest number of alleles per open-pollinated variety (55.25) was detected in Shanxi germplasm, which indicated that open-pollinated varieties from Shanxi possessed the largest genetic diversity among those from the five locations. The correlation coefficients between different genetic similarity matrices suggested that 200 alleles were sufficient for analysis of the genetic diversity of these 44 open-pollinated varieties. The cluster analysis showed that 44 open-pollinated varieties collected from three growing regions in China were accurately classified into three groups that were highly consistent with their geographic origins, and there is no correlation between GS and geographic distance in this study.

This paper reported firstly successful cloning of lycopene ε-cyclase (IbLCYe) gene from sweetpotato, Ipomoea batatas (L.) Lam. Using rapid amplification of cDNA ends (RACE), IbLCYe gene was cloned from sweetpotato cv. Nongdafu 14 with high carotenoid content. The 1 805 bp cDNA sequence of IbLCYe gene contained a 1 236 bp open reading frame (ORF) encoding a 411 amino acids polypeptide with a molecular weight of 47 kDa and an isoelectric point (pI) of 6.95. IbLCYe protein contained one potential lycopene ε-cyclase domain and one potential FAD (flavinadenine dinucleotide)/NAD(P) (nicotinamide adenine dinucleotide phosphate)-binding domain, indicating that this protein shares the typical characteristics of LCYe proteins. The gDNA of IbLCYe gene was 4 029 bp and deduced to contain 5 introns and 6 exons. Real-time quantitative PCR analysis revealed that the expression level of IbLCYe gene was significantly higher in the storage roots of Nongdafu 14 than those in the leaves and stems. Transgenic tobacco (cv. Wisconsin 38) expressing IbLCYe gene accumulated significantly more β-carotene compared to the untransformed control plants. These results showed that IbLCYe gene has an important function for the accumulation of carotenoids of sweetpotato.

The contents of carotenoids in the storage root of sweetpotato, Ipomoea batatas (L.) Lam. vary dramatically among different cultivars. However, so far little is known about the regulation of carotenoids synthesis in sweetpotato. In our laboratory, we identified a novel sweetpotato mutant, Nongdafu 14, which is a homogenous mutant derived from the wild type Kokei No. 14. The contents of carotenoids in the storage root of Nongdafu 14 were analyzed using high performance liquid chromatography (HPLC), and it was found that the amount of carotenoids, b-carotene, lutein and zeaxantion, three major types of carotenoids in sweetpotato storage roots, increased 2-26 folds in Nongdafu 14 compared to Kokei No. 14. Suppression subtractive hybridization (SSH) was used to identify genes that were differentially expressed in Nongdafu 14, and a differentially expressed cDNA library was constructed using the cDNA of Nongdafu 14 storage roots as tester and that of Kokei No. 14 storage roots as driver. Out of the 1 530 clones sequenced, we identified 292 nonredundant ESTs. GO and KEGG analyses of these differentially expressed ESTs indicated that diverse metabolism pathways were affected and candidate genes involved in regulation of carotenoids synthesis are suggested.

This research focuses on the impact of family’s human capital on social mobility in China’s rural community. Empirical research is conducted based on data from surveying a typical rural community in the past 20 yr. The study indicates that social mobility in rural area is active in the past 20 yr, and the human capital of family, represented by primary labor’s education level, has played an essential role in mobility of low social class. Meanwhile, socio-economic development and the change of supply and demand in labor market dims the signaling role of degree education, but the impact of occupational training is increasingly remarkable. Therefore, the change from sole degree education to multi-leveled education including occupational education and training is a main way for China’s rural families in low class to realize social mobility.

To elucidate the differential gene expression patterns in soybeans during infection by Phytophthora sojae, a cDNA libraryfor suppression subtractive hybridization (SSH) was constructed with cDNAs from soybean cultivar Suinong 10 treatedwith sterile distilled water as the driver and cDNAs from Suinong 10 inoculated with P. sojae as the tester. A total of 2 067recombinant colonies from the SSH library were randomly picked, amplified, and sequenced. After discarding 312 poorquality expressed sequence tags (EST), 1 755 high quality ESTs were assembled and edited to 1 384 tentatively uniquegenes (TUG), in which, 586 showed significant homology to known sequences, and 798 had low homology or no matchwith the known sequences. A cDNA microarray containing 307 singletons from the 586 TUGs and 222 singletons from the798 TUGs was developed to characterize differentially expressed cDNAs in the SSH library, and eight cDNAs wereidentified to be up-regulated after microarray analysis and then confirmed by real-time PCR. They were homologous to theprotein 10, and were also related to some proteins in disease resistance response, such as pathogen-related protein,phenylalanine ammonia-lyase, isoflavone reductase, WRKY transcription factor 31, major allergen Pru ar 1, and pleiotropicdrug resistance protein 12. Most of the up-regulated cDNAs encode enzymes of phytoalexin biosynthesis andpathogenesis-related proteins involved in plant disease resistance. Here, we fist reported the Pru ar 1 in soybeans. Thefindings of this research have contributed to better understanding of soybean resistance to P. sojae at the molecular level.

We investigated the size distribution of water-stable aggregates and the soil carbon, nitrogen and phosphorus concentration
over aggregate size fractions based on a long-term (1990-2006) fertilization experiment in a reddish paddy soil. The results
showed that the largest water-stable aggregate (WSA) (>5 mm) and the smallest WSA (<0.25 mm) took up the first largest
proportion (38.3%) and the second largest proportion (23.3%), respectively. Application of organic materials increased
the proportion of the large WSA (>2 mm) and decreased the proportion of the small WSA (<1 mm), resulting in an increase
in the mean weight diameter of WSA, whereas application of chemical fertilizer had little effect. Application of organic
materials, especially combined with chemical fertilizers, increased total carbon, nitrogen and phosphorus concentrations
in all sizes of WSA, and total carbon, nitrogen and phosphorus were prone to concentrate in the large WSA. Further more,
application of organic materials improved the supply effectiveness of available phosphorus, whereas had little influence
on the labile carbon in WSA. Application of chemical fertilizers improved concentrations of total and available phosphorus
in all sizes of WSA, whereas had little influence on total carbon and nitrogen contents. Economical fertilization model
maintained the soil fertility when compared with full dose of chemical fertilizers, indicating that using organic materials
could reduce chemical fertilizers by about one third.We investigated the size distribution of water-stable aggregates and the soil carbon, nitrogen and phosphorus concentration over aggregate size fractions based on a long-term (1990-2006) fertilization experiment in a reddish paddy soil. The results showed that the largest water-stable aggregate (WSA) (>5 mm) and the smallest WSA (<0.25 mm) took up the first largest proportion (38.3%) and the second largest proportion (23.3%), respectively. Application of organic materials increased the proportion of the large WSA (>2 mm) and decreased the proportion of the small WSA (<1 mm), resulting in an increase in the mean weight diameter of WSA, whereas application of chemical fertilizer had little effect. Application of organic materials, especially combined with chemical fertilizers, increased total carbon, nitrogen and phosphorus concentrations in all sizes of WSA, and total carbon, nitrogen and phosphorus were prone to concentrate in the large WSA. Further more, application of organic materials improved the supply effectiveness of available phosphorus, whereas had little influence on the labile carbon in WSA. Application of chemical fertilizers improved concentrations of total and available phosphorus in all sizes of WSA, whereas had little influence on total carbon and nitrogen contents. Economical fertilization model maintained the soil fertility when compared with full dose of chemical fertilizers, indicating that using organic materials could reduce chemical fertilizers by about one third.

To establish a suitable and effective protocol of protein extraction for two-dimensional gel electrophoresis (2-DE) analysis in kenaf leaf tissues, three extraction methods (trichloroacetic acid/acetone, urea/thiourea, and phenol extraction methods) were applied to the extraction of kenaf leaf protein. The results were compared in regard to protein extraction efficiency, sodiumdodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), and 2-DE gels. Furthermore, the 2-DE system was optimized for four aspects: the pH range of IPG (immobilized pH gradient) stripes, sampling methods, sample volumes, and concentration of polyacrylamide gels. The data presented showed that the phenol extraction method is the best method to perform 2-DE analysis of kenaf leaf protein. The protein extracted from phenol extraction method reached the purity of (26.40±0.859)%, showed (25.67±1.53) protein bands in one dimension SDS-PAGE gels, and (1 374±54.44) protein spots on 2-DE gels. The research also indicates that kenaf leaf protein spots were distributed mainly within the pH range of 4-8. More clear background with a better distribution effect and many protein spots could be obtained on 2-DE gels under the conditions of active rehydration loading, 24 cm IPG strips (linear pH gradient of 4-7), 1.4 mg samples, and 12% SDS-PAGE gels.