Genetic Variation of Host Populations of Liriomyza sativae Blanchard

In this study, partial sequences of the mitochondrial cytochrome oxidase subunit I （mtDNA-COI） gene and the ribosomal internal transcribed spacer 1 （rDNA-ITS 1） gene, isolated from five artificial populations of Liriomyza sativae （Diptera： Agromyzidae）, were sequenced and compared, to analyze their genetic variation. Analysis of the mtDNA-CO1 gene showed that a low genetic variation was detected among the five populations and only five variable sites were found in the nucleotide sequences. Most of the observed variations that occurred within the populations were because of nucleotide transitions, whereas, the interpopulation variation was because of the differences in haplotype frequencies occurring among the host populations. Analysis of the rDNA-ITS1 gene revealed a small diversity in the five host populations. The trend of genetic differentiation in the host populations was consistent with the preference of L. sativae to the plant hosts.

Genetic Variations Among Liriomyza sativae Blanchard Populations Indicated by β-tubulin Gene Sequences

To analyze the genetic differentiation of the host- and geo-populations of Liriomyza sativae Blanchard, the β-tubulin gene of 5 host-populations and 6 geo-populations of L. sativae was sequenced. Subsequently, the sequences were analyzed by biosoftware DNAStar and MEGA, and the phylogenetic trees constructed. The results obtained by the two softwares were similar, that is, the sequences of β-tubulin gene were more than 98% homologous, among the host- and geo-populations of L. sativae, with only 8 variable sites, but no insertions and deletions were detected. It seems that differentiations in β-tubulin gene among the host- and geo-populations of L. sativae are related to the hobby to hosts and the geographical distributions, respectively.

美洲斑潜蝇(Lironyza sativae Blanchard)发生及综合治理技术研究

美洲毫潽蝇是严重危害菜、瓜果等经济作物的重要植物检疫性害虫,其害虫范围广、繁殖能力强、虫体小、历期短、世代重叠严重,防治困难。该虫1994年传入我国,并迅速蔓延危害,国内分布已达二十余个省、市、自治区,成为农业生产上的一大难题。1996—1998年,我们对其发生及综合治理技术进行了深入研究,现报道如下: 1、生物学特性及发生消长规律 多年调查表明,美洲毫潽蝇在本地大田一年发生8—10代,不能越冬:在冬暖蔬菜大棚内发生3—4代,成为翌年虫源。

天门市水稻病虫害绿色防控技术示范

介绍天门市水稻(Oryza sativa L.)病虫害绿色防控技术的示范情况与成效,集成了一套以生态防控、物理诱杀、生物防治和化学农药减量增效为主的防控技术模式,厘清防控措施实施中存在的问题,提出加强农产品质量安全监管、打造绿色农产品品牌、加强宣传培训、加大政策与资金投入的对策与建议,为农作物病虫害绿色防控提供参考。

水稻雄性不育突变体tpa1的表型鉴定与精细定位

雄性不育材料是杂交水稻育种的关键。本研究通过甲基磺酸乙酯(ethyl methane sulfonate,EMS)诱变优良籼稻保持系西农1B,筛选得到一个雄性不育突变体tpa1。tpa1在营养生长阶段与野生型无差异,生殖生长阶段表现雄配子不育,雌配子发育正常。表型观察发现,tpa1花粉完全破碎消失,花药外壁角质层异常,花药内壁乌式体排列异常,胼胝质合成异常,绒毡层凋亡异常,且花粉外壁缺失柱状层。遗传分析表明该突变性状受1对隐性核基因控制,利用突变体tpa1与缙恢10号构建遗传群体,最终将TPA1基因定位于4号染色体引物标记N9和N11之间,物理距离为74 kb,该区间共15个预测基因,通过重测序仅发现在LOC_Os04g53380的外显子上发生了单碱基替换,导致了翻译的提前终止,随后对野生型和突变体tpa1该位点进行测序证实了这一突变,因此将该基因确定为TPA1的候选基因,TPA1是一个未被报道过的新的雄性不育基因。本研究将为TPA1基因的功能研究奠定基础。

天津市不同地域九个粳稻品种种子的耐贮藏性分析

对9个水稻(Oryza sativa L.)品种在天津市11个地区收获的种子进行自然老化试验,分析不同地区不同品种水稻种子相同储存条件下的发芽率、根长和芽长。结果表明,同一地区的不同品种间差异明显;天津市不同地区收获的同一水稻品种,自然老化后发芽率差异明显,其中津南生长的水稻品种的耐贮藏性普遍优于其他地区。

Transcription factor OsSPL10 interacts with OsJAmyb to regulate blast resistance in rice

Transcription factors(TFs)play essential roles in transcriptional reprogramming during activation of plant immune responses to pathogens.OsSPL10(SQUAMOSA promoter binding protein-like10)is an important TF regulating trichome development and salt tolerance in rice.Here we report that knockout of OsSPL10 reduces whereas its overexpression enhances rice resistance to blast disease.OsSPL10 positively regulates chitin-induced immune responses including reactive oxygen species(ROS)burst and callose deposition.We show that OsSPL10 physically associates with OsJAmyb,an important TF involved in jasmonic acid(JA)signaling,and positively regulates its protein stability.We then prove that OsJAmyb positively regulates resistance to blast.Our results reveal a molecular module consisting of OsSPL10 and OsJAmyb that positively regulates blast resistance.

OsWRKY65 enhances immunity against fungal and bacterial pathogens in rice

Diverse bacterial and fungal pathogens attack plants,causing biotic stress and severe yield losses globally.These losses are expected to become more serious as climate change improves conditions for many pathogens.Therefore,identifying genes conferring broad-spectrum disease resistance and elucidating their underlying mechanisms provides important resources for plant breeding.WRKY transcription factors affect plant growth and stress responses.However,the functions of many WRKY proteins remain to be elucidated.Here,we demonstrated the role of rice(Oryza sativa)WRKY groupⅢtranscription factor OsWRKY65 in immunity.OsWRKY65 localized to the nucleus and acted as transcriptional repressor.Genetic and molecular functional analyses showed that OsWRKY65 increases resistance to the fungal pathogen Fusarium fujikuroi through downregulation of GA signaling and upregulation of JA signaling.Moreover,OsWRKY65 modulated the expression of the key genes that confer susceptibility or resistance to Xanthomonas oryzae pv.oryzae to enhance immunity against the pathogen.In particular,OsWRKY65directly bound to the promoter region of OsSWEET13 and repressed its expression.Taken together,our findings demonstrate that the OsWRKY65 enhances resistance to fungal and bacterial pathogens in rice.

The OsBSK1-2-MAPK module regulates blast resistance in rice

Receptor-like cytoplasmic kinase OsBSK1-2 was reported to play an important role in regulation of response to rice blast,but the signaling pathway remained unknown.In this study,we identified OsMAPKKK18 and previously uncharacterized MAPKKKs OsMAPKKK16 and OsMAPKKK19 that interact with OsBSK1-2.Expression of all three MAPKKKs was induced by Magnaporthe oryzae infection,and all three induced cell death when transiently expressed in Nicotiana benthamiana leaves.Knockout of OsMAPKKK16 and OsMAPKKK18 compromised blast resistance and overexpression of OsMAPKKK19 increased blast resistance,indicating that all three MAPKKKs are involved in regulation of rice blast response.Furthermore,both OsMAPKKK16 and OsMAPKKK19 interacted with and phosphorylated OsMKK4 and OsMKK5,and chitin-induced MAPK activation was suppressed in osmapkkk16 and osbsk1-2 mutants.OsMAPKKK18 was earlier reported to interact with and phosphorylate OsMKK4 and affect chitin-induced MAPK activation,suggesting that OsBSK1-2 is involved in regulation of immunity through multiple MAPK signaling pathways.Unlike BSK1 in Arabidopsis,OsBSK1-2 was not involved in response to avirulent M.oryzae strains.Taken together,our results revealed important roles of OsMAPKKK16/18/19 and a OsBSK1-2-OsMAPKKK16/18/19-OsMKK4/5 module in regulating response to rice blast.

Carbon Catabolite Repressor UvCreA is Required for Development and Pathogenicity in Ustilaginoidea virens

The rice false smut disease, caused by Ustilaginoidea virens, has emerged as a significantglobal threat to rice production. The mechanism of carbon catabolite repression plays a crucial role in theefficient utilization of carbon nutrients and enzyme regulation in the presence of complex nutritionalconditions. Although significant progress has been made in understanding carbon catabolite repression infungi such as Aspergillus nidulans and Magnaporthe oryzae, its role in U. virens remains unclear. Toaddress this knowledge gap, we identified UvCreA, a pivotal component of carbon catabolite repression,in U. virens. Our investigation revealed that UvCreA localized to the nucleus. Deletion of UvCreA resultedin decreased growth and pathogenicity in U. virens. Through RNA-seq analysis, it was found that theknockout of UvCreA led to the up-regulation of 514 genes and down-regulation of 640 genes. Moreover,UvCreA was found to be involved in the transcriptional regulation of pathogenic genes and genesassociated with carbon metabolism in U. virens. In summary, our findings indicated that UvCreA isimportant in fungal development, virulence, and the utilization of carbon sources through transcriptionalregulation, thus making it a critical element of carbon catabolite repression.

Irrigation regimes modulate non-structural carbohydrate remobilization and improve grain filling in rice(Oryza sativa L.)by regulating starch metabolism

Recently developed ‘super’ rice cultivars with greater yield potentials often suffer from the problem of poor grain filling, especially in inferior spikelets. Here, we studied the activities of enzymes related to starch metabolism in rice stems and grains, and the microstructures related to carbohydrate accumulation and transportation to investigate the effects of different water regimes on grain filling. Two ‘super’ rice cultivars were grown under two irrigation regimes of well-watered(WW) and alternate wetting and moderate soil drying(AWMD). Compared with the WW treatment,the activities of ADP glucose pyrophosphorylase(AGPase), starch synthase(StSase) and starch branching enzyme(SBE), and the accumulation of non-structural carbohydrates(NSCs) in the stems before heading were significantly improved, and more starch granules were stored in the stems in the AWMD treatment. After heading, the activities of α-amylase, β-amylase, sucrose phosphate synthase(SPS) and sucrose synthase in the synthetic direction(SSs)were increased in the stems to promote the remobilization of NSCs for grain filling under AWMD. During grain filling, the enzymatic activities of sucrose synthase in the cleavage direction(SSc), AGPase, StSase and SBE in the inferior spikelets were increased, which promoted grain filling, especially for the inferior spikelets under AWMD.However, there were no significant differences in vascular microstructures. The grain yield and grain weight could be improved by 13.1 and 7.5%, respectively, by optimizing of the irrigation regime. We concluded that the low activities of key enzymes in carbon metabolism is the key limitation for the poor grain filling, as opposed to the vascular microstructures, and AWMD can increase the amount of NSC accumulation in the stems before heading, improve the utilization rate of NSCs after heading, and increase the grain filling, especially in the inferior spikelets, by altering the activities of key enzymes in carbon metabolism.

The auxin transporter OsAUX1 regulates tillering in rice(Oryza sativa)

Tillering is an important agronomic trait of rice(Oryza sativa)that affects the number of effective panicles,thereby affecting yields.The phytohormone auxin plays a key role in tillering.Here we identified the high tillering and semi-dwarf 1(htsd1)mutant with auxin-deficiency root characteristics,such as shortened lateral roots,reduced lateral root density,and enlarged root angles.htsd1 showed reduced sensitivity to auxin,but the external application of indole-3-acetic acid(IAA)inhibited its tillering.We identified the mutated gene in htsd1 as AUXIN1(OsAUX1,LOC_Os01g63770),which encodes an auxin influx transporter.The promoter sequence of OsAUX1 contains many SQUAMOSA PROMOTER BINDING PROTEIN-LIKE(SPL)binding sites,and we demonstrated that SPL7 binds to the OsAUX1 promoter.TEOSINTE BRANCHED1(OsTB1),a key gene that negatively regulates tillering,was significantly downregulated in htsd1.Tillering was enhanced in the OsTB1 knockout mutant,and the external application of IAA inhibited tiller elongation in this mutant.Overexpressing OsTB1 restored the multi-tiller phenotype of htsd1.These results suggest that SPL7 directly binds to the OsAUX1 promoter and regulates tillering in rice by altering OsTB1 expression to modulate auxin signaling.

Rice AGL1 determines grain size and sterile lemma identity

The grass spikelet is a unique inflorescence structure that determines grain size.Although many genetic factors have been well characterized for grain size and glume development,the underlying molecular mechanisms in rice are far from established.Here,we isolated rice gene,AGL1 that controlled grain size and determines the fate of the sterile lemma.Loss of function of AGL1 produced larger grains and reduced the size of the sterile lemma.Larger grains in the agl1 mutant were caused by a larger number of cells that were longer and wider than in the wild type.The sterile lemma in the mutant spikelet was converted to a rudimentary glume-like organ.Our findings showed that the AGL1(also named LAX1)protein positively regulated G1 expression,and negatively regulated NSG1 expression,thereby affecting the fate of the sterile lemma.Taken together,our results revealed that AGL1 played a key role in negative regulation of grain size by controlling cell proliferation and expansion,and supported the opinion that rudimentary glume and sterile lemma in rice are homologous organs.

SUPER WOMAN 2(SPW2)maintains organ identity in spikelets by inhibiting the expression of floral homeotic genes OsMADS3,OsMADS58,OsMADS13,and DROOPING LEAF

Flower organ identity in rice is mainly determined by the A-,B-,C-and E-class genes,with the majority encoding MADS-box transcription factors.However,few studies have investigated how the expression of these floral organ identity genes is regulated during flower development.In this study,we identified a gene named SUPER WOMAN 2(SPW2),which is necessary for spikelet/floret development in rice by participating in the regulation of the expression of pistil identity genes such as OsMADS3,OsMADS13,OsMADS58 and DL.In the spw2 mutant,ectopic stigma/ovary-like tissues were observed in the non-pistil organs,including sterile lemma,lemma,palea,lodicule,and stamen,suggesting that the identities of these organs were severely affected by mutations in SPW2.SPW2 was shown to encode a plant-specific EMF1-like protein that is involved in H3K27me3 modification as an important component of the PRC2 complex.Expression analysis showed that the SPW2 mutation led to the ectopic expression of OsMADS3,OsMADS13,OsMADS58,and DL in non-pistil organs of the spikelet.The ChIP-qPCR results showed significant reductions in the levels of H3K27me3 modification on the chromatin of these genes.Thus,we demonstrated that SPW2 can mediate the process of H3K27me3 modification of pistil-related genes to regulate their expression in non-pistil organs of spikelets in rice.The results of this study expand our understanding of the molecular mechanism by which SPW2 regulates floral organ identity genes through epigenetic regulation.

Modified Atmospheric Packaging and Its Effect on Postharvest Cannabis Quality

Cannabis sativa L. is used as fiber, food, and medicine in several countries. Though it is illegal for recreational use in most of the world, there are some countries that have legalized production and sale. There is a lot of research on production of cannabis, but less so on storage technologies. Cannabis contains several high value compounds, such as cannabinoids and terpenoids, that are susceptible to degradation via light, temperature, and oxygen. Several studies have explored temperature and light, and industry has adjusted accordingly. However, less is known about oxygen-induced degradation. Biochemical studies have demonstrated oxidative degradation of high value compounds, and many producers use some form of modified atmospheric packaging (MAP) for storage. However, the efficacy of MAP is unclear. The objective of this paper is to review our current understanding of MAP in postharvest cannabis storage and identify avenues where additional research is needed.

硅基叶面阻控剂对水稻的控镉效应

在中轻度Cd污染区域开展大田试验,探索不同用量的硅基叶面阻控剂对土壤有效Cd、水稻(Oryza sativa L.)不同器官Cd含量及Cd转运的影响。结果表明,叶面阻控剂不能降低土壤有效Cd含量,但能调控Cd在水稻器官中的转运与富集,与不施叶面阻控剂对照相比,水稻根、茎、叶与稻米中Cd含量分别降低13.06%~27.03%、17.39%~36.96%、14.89%~42.55%、11.11%~32.83%,水稻对Cd的富集从高到低依次为根、茎、叶、稻米。水稻植株中Cd从根到茎(TF根-茎)、茎到叶(TF茎-叶)、叶到稻米(TF叶-稻米)的转运系数分别为0.36~0.42、0.47~0.53、0.42~0.50,其中根到茎的转运系数最低,且随叶面阻控剂用量的增加其转运系数逐渐降低。施用一定量的叶面阻控剂在一定程度上能提高水稻产量,从经济成本和降镉效果等因素综合考虑,用量为4 500 mL/hm~2时,成本低廉且效果较佳。

Abamectin resistance in strains of vegetable leafminer, Liriomyza sativae （Diptera： Agromyzidae） is linked to elevated glutathione S-transferase activity

Abamectin resistance was selected in the vegetable leafminer, Liriomyza sativae （Blanchard） （Diptera： Agromyzidae） under laboratory conditions, and cross- resistance patterns and possible resistance mechanisms in the abamectin-resistant strains （AL-R, AF-R） were investigated. Compared with the susceptible strain （SS）, strain AL-R displayed 39-fold resistance to abamectin after 20 selection cycles during 25 generations, and strain AF-R exhibited 59-fold resistance to abamectin after 16 selection cycles during 22 generations. No cross-resistance to cyromazine was found in both abamectin-resistant strains. However, we failed to select for cyromazine resistance in L. sativae under laboratory conditions by conducting 17 selection cycles during 22 generations. However, moderate levels of cross-resistance to abamectin （6-9 fold） were observed in strains which received cyromazine treatments. Biochemical analysis showed that glutathione S-transferase （GST） activity in both abamectin-resistant strains （AL-R, AF-R） was significantly higher than in the susceptible strain （SS）, suggesting metabolically driven resistance to abamectinin L. sativae. Recommendations of mixtures or rotation of cyromazine and abamectin should be considered carefully, as consecutive cyromazine treatments may select for low-level cross-resistance to abamectin.

Comparative demography of Liriomyza sativae Blanchard （Diptera： Agromyzidae） on cucumber at seven constant temperatures

Reproduction and population parameters of vegetable leafminer, Liriomyza sativae Blanchard were measured on cucumber （Cucumis sativus L.） at seven constant temperatures （10, 15, 20, 25, 30, 35 and 40℃）. No eggs were found at 10℃ and flies died after exposure to 40℃. The significantly highest intrinsic rate of natural increase （rm）, net reproductive rate （R0） and finite rate of increase （λ） ofL. sativae were obtained at 25℃ as 0.196, 52.452, and 1.216, respectively. The above-mentioned parameters decreased at 15℃ and 135℃ and this reduction at 35℃ was strong. Doubling time （DT） varied significantly with temperature. The shortest doubling time was obtained at 25℃. Mean generation time （T） decreased significantly with increasing temperature between 15℃ and 35℃. Percentage of immature ages in the stable age distribution was more than 95% at all temperatures. Female longevity was greater than male at all temperatures. Liriomyza sativae lived for a long time at 15℃, whereas at 35℃ had lower survival rates. The effect of temperature on reproduction, especially the intrinsic rate of increase of L. sativae would be useful for predicting its longterm population fluctuation over several generations.

新型肥料在稻-油轮作制中的施用效果

为探索轮作周期中不同肥料高效施用技术,通过田间定位试验,设置了不施肥(T1)、常规化肥(T2)、缓控释肥(T3)、稳定性肥料(T4)、BB肥(T5)和在T2的基础上增施生物有机肥(T6)6个处理,研究了不同肥料施用对稻(Oryza sativa L.)-油(Brassica campestris L.)轮作制度下作物产量及养分利用效率的影响。结果表明,与施用常规化肥处理相比,施用缓控释肥和在常规化肥基础上增施有机肥均可提高水稻和油菜及周年产量,大部分轮作年份达显著水平(P<0.05);不同肥料处理均能提高稻-油轮作水稻季、油菜季及周年作物氮、磷、钾的吸收量和农学利用效率,其中以T6处理效果最好,氮、磷、钾吸收量和农学利用效率均与施用常规化肥处理差异达显著水平(P<0.05),T3处理效果次之,除油菜季磷吸收量外,其他均与施用常规化肥处理差异达显著水平(P<0.05)。综合来看,湖北省稻-油轮作制中施用缓控释肥和增施生物有机肥效果较好,施用BB肥和稳定性肥料的效果略差。

水稻开颖突变体的遗传分析和基因克隆

花器是种子生成的基础,水稻花器发育直接影响稻谷产量与品质。源美丝苗与P704杂交后代中发现一株开颖突变体(oh,open-hull),其穗部发育有缺陷,主要表现为:开颖,结实率显著下降,种子变小。遗传分析发现开颖表型由一对隐性细胞核基因控制。通过BSA分析,开颖基因被定位于水稻第3染色体上,检索发现候选区间与Os MADS1(LOC_Os03g11614)基因重合,与蜀恢498参考基因序列进行比对,oh中OsMADS1的第一外显子第118位发生碱基颠换,导致编码的天冬氨酸变成酪氨酸,将该等位基因命名为OsMADS1^(oh)。从oh中克隆OsMADS1^(oh)并构建过表达载体,通过农杆菌介导转入易转化材料(中花11)中,转基因后代出现开颖表型,证实OsMADS1^(oh)导致开颖。另外,RNA定量分析结果表明,MADS8和YABB5的表达受OsMADS1调控。本研究从育种材料中筛选到开颖突变体,并从中鉴定了新的Os MADS1等位基因,为阐明花器形成的分子机理研究提供了特异种质和基因资源。