Genome-wide association study for spot blotch resistance in Afghan wheat germplasm

Spot blotch (SB), caused by Bipolaris sorokiniana, is a devastating disease of wheat globally, especially in South Asia and South America. Understanding the genetics of resistance to SB is important for developing breeding strategies to improve resistance. A panel of 301 genotypes from Afghanistan was phenotyped over two crop seasons using a mixture of virulent B. sorokiniana isolates and genotyped using DArTSeq to obtain genome-wide markers. Fifty genotypes (16.6%) showed disease scores less than the resistant control. Principal component analysis using the genotypic data clustered the genotypes into five different groups. Among models used for genome-wide association mapping, the multilocus mixed model, and fixed and random model circulating probability unification algorithms were most effective in identifying significant marker-trait associations (MTA). Twenty-five MTAs at p ≤ .001 were identified on chromosomes 1A, 1B, 1D, 2B, 2D, 3A, 3B, 4A, 5A, 5B, 6A, 7A, and 7D, indicating the quantitative nature of resistance to SB. Phenotypic variation explained by these markers ranged from 2.0% to 17.7%, and genomic regions on the chromosomes 1D, 2D, 3A, 3B, 4A, 5A, and 5B coincided with loci identified in previous studies. Three single nucleotide polymorphism (SNP) markers on chromosomes 1B (SNP 1113207) and 5A (SNPs 5411867 and 998276) were significant in both crop seasons as well as in the combined analysis across seasons. Marker 5411867 is close to Vrn-A1, shown to be associated with SB in previous studies. Furthermore, among known SB resistance genes, Sb2 on chromosome 5B was predicted to be significant in this panel.     

Season-long expression of Cry1Ac and Cry2Ab proteins in Bollgard II cotton in Australia

Bollgard II cotton has been grown commercially in Australia since 2003 for control of the primary target species Helicoverpa armigera (Hübner) and Helicoverpa punctigera (Wallengren) Larvae of both species have been reported to survive at low frequencies on Bollgard II with larvae >8 mm recorded in between 7 and 18% of the area planted to Bollgard II cotton between 2005/06 and 2007/08. F₁ and F₂ tests have shown that this is not due to the presence of resistance genes in the surviving larvae. To understand if fluctuations in the expression of the Cry proteins in Bollgard II allow some larvae to survive, plant tissue samples were taken from five Bollgard II cultivars throughout the growing season within fields and from different farms within a production region between 2007 and 2010. The data indicate that the expression of both Cry proteins is similar to the known resistance-monitoring diagnostic concentrations and relatively uniform between fields within a farm and between farms within a region, with less than one-third of the tests at this level of variation being significant. However, there were intra-seasonal changes in expression of both Cry proteins and differences in expression between plant structures and between cultivars for both Cry proteins. Further work is needed to establish if this variation in Cry protein content in Bollgard II cotton affects the control of Helicoverpa spp. in the field or whether plant-physiological and pest-behavioural factors underlie the occasional occurrence of Helicoverpa larval survival on Bollgard II cotton.     

基于mtCOI基因序列的我国云南省和缅甸、柬埔寨草地贪夜蛾种群遗传多样性分析

为制定有效的草地贪夜蛾防控措施,分别自缅甸、柬埔寨和我国云南省采集4、2和8个种群共542个草地贪夜蛾样品,基于mtCOI基因序列分析这14个种群的遗传多样性指数、遗传分化系数及基因流。结果表明,缅甸草地贪夜蛾种群的单倍型多样性指数和平均核苷酸差异数分别介于0.273～0.396和4.643～6.727之间,高于我国云南省的草地贪夜蛾种群,分别介于0.047～0.214和0.791～3.636之间;除ZT种群、LS种群和TO种群外,其它11个种群的Fu’s F均为显著正值,表明缅甸、柬埔寨和我国云南省的草地贪夜蛾种群未经历种群扩张事件;在14个种群中,LS种群与其它种群分化较明显,TK种群、MY种群、CP种群、MS种群和KY种群有效迁入个数和有效迁出个数之和较高,分别为699.41、682.50、855.76、684.56和701.31,推测这5个种群在草地贪夜蛾基因交流中起着类似"中转站"的作用。     

Evaluation of infiltration models and field-saturated hydraulic conductivity in situ infiltration tests during the dry season

Paddy and Water Environment - Field-saturated hydraulic conductivity (Kfs) is an important parameter used to estimate field water requirements in irrigation systems, although it is widely...     

Characteristics of Livestock Husbandry and Management Practice in the Central Dry Zone of Myanmar

Tropical Animal Health and Production - The central dry zone of Myanmar is the area with the highest density of small-scale livestock farmers under harsh environmental condition. In this study, we...     

2019年缅甸草地贪夜蛾发生情况考察报告

缅甸是我国草地贪夜蛾的重要境外虫源区, 为了掌握草地贪夜蛾在缅甸的发生与防控情况, 2019年5月19-25日, 云南省农业科学院与缅甸农业研究司专家联合对缅甸南部、中部、中北部和东部草地贪夜蛾开展了实地调查。结果表明: 缅甸全境均有草地贪夜蛾发生, 为害严重, 田间多种虫态并存。其中, 南部玉米大部分已经收获, 虫株率62.50%~97.50%; 中部区域种植少量的商品甜玉米, 防治到位, 虫株率6.00%~7.50%; 中北部曼德勒敏建玉米种植面积最大, 达8 000 hm2, 80%的地块已成熟收获, 处于吐丝-乳熟期的田块虫株率达100%, 受害严重; 东部掸邦虫株率59%, 虫口密度2.60头/株。玉米是缅甸第二大种植作物, 全年玉米种植面积达47万~52万hm2, 其中与我国云南接壤的东部掸邦是主要种植区。到5月前因无有效降雨, 全境玉米尚未大面积种植, 仅有零星种植, 随着雨季的来临, 玉米种植面积将全面增加, 草地贪夜蛾种群数量也将随之增加。因此, 加强与缅甸相关部门合作, 密切掌握缅甸玉米种植及草地贪夜蛾的发生与防控情况, 对我国草地贪夜蛾的监测预警及防控有重要的参考价值。     

Serological evidence of avian influenza virus subtype H5 and H9 in live bird market,Myanmar

Avian Influenza (AI), caused by Alphainfluenzaviruses (AIVs), is a contagious respiratory disease in birds and mammals. AIVs have been reported in poultry worldwide and the impact of AIVs on human health is immense. In this study, a serological survey of AIV subtype H5 and H9 was conducted in a live bird market (LBM) in Yangon, Myanmar during February 2016 to September 2016. A total of 621 serum samples were collected from chickens (n = 489) and ducks (n = 132) from 48 vendors in the LBM. The samples were examined for antibodies against influenza viruses by using NP-ELISA and specific antibodies against AIV-H5N1 (Clade 2.3.4) and AIV-H9N2 (Clade 9.4.2) by using Hemagglutination Inhibition (HI) assay. The result of NP-ELISA assay showed that 12.88 % (80/621) of poultry in LBM was positive for AIV antibodies. In detail, 38.06 % (51/134) of layers, 7.08 % (8/113) of backyard chicken, 2.07 % (5/242) of broilers and 12.12 % (16/132) of ducks were AIV positive. The HI test for specific antibodies against AIV-H5N1 and AIV-H9N2 were 1.77 % (11/621) and 4.51 % (28/621), respectively. Our findings revealed the evidence of AIV-H5N1 and AIV-H9N2 exposure in both chicken and ducks in the LBM in Yangon, Myanmar. Risks of influenza infections and transmission among poultry and humans in the LBMs could not be ignored.     

Population structure of Nga Myin Yinn Silonia silondia in the Ayeyarwady River,Myanmar, by mitochondrial DNA markers

Fisheries Science - The Silond catfish Silonia silondia, locally known as Nga Myin Yinn, is a commercially important fish in Myanmar; however, fundamental knowledge of its population structure is...     

Microbiological properties of Myanmar traditional shrimp sauce,hmyin-ngan-pya-ye

Fisheries Science - The microbiological properties of Myanmar traditional fermented products were characterized using four different brands of bottled shrimp sauce products sold frequently at a...