Heritability of spotted wilt resistance in a Florida‐EP™ “113”‐derived peanut (Arachis hypogaea) population

Spotted wilt, caused by tomato spotted wilt virus (TSWV), is a major disease of peanut (Arachis hypogaea ) in the south‐eastern United States. Cultivar resistance is the most important factor in disease control. However, spotted wilt resistance in current cultivars still carries risk in the absence of other practices when disease is severe. In contrast, a newly developed cultivar, Florida‐EP? “113,” has demonstrated excellent resistance even when spotted wilt is severe. Information on heritability of this resistance can help breeders better utilize it in breeding. F₂‐derived populations from the cross Florida‐EP? “113”/Georgia Valencia were developed and tested in field experiments in Florida from 2012 to 2014. Disease symptoms were evaluated visually, and the frequency of TSWV infection was measured by ImmunoStrip^®. Heritability estimated from ImmunoStrip^® was higher (0.66) compared to visual ratings (0.48). Genetic correlations among evaluation methods (r _A = 0.92–0.99) and environments (r _B = 0.86–0.99) were high. These results indicate that resistance in Florida‐EP? “113” is highly heritable and that selection in a high disease risk environment is feasible without significant erosion of genetic gain.     

Novel α-Amylase Inhibitor Hemi-Pyocyanin Produced by Microbial Conversion of Chitinous Discards

α-Amylase inhibitors (aAIs) have been applied for the efficient management of type 2 diabetes. The aim of this study was to search for potential aAIs produced by microbial fermentation. Among various bacterial strains, Pseudomonas aeruginosa TUN03 was found to be a potential aAI-producing strain, and shrimp heads powder (SHP) was screened as the most suitable C/N source for fermentation. P. aeruginosa TUN03 exhibited the highest aAIs productivity (3100 U/mL) in the medium containing 1.5% SHP with an initial pH of 7–7.5, and fermentation was performed at 27.5 °C for two days. Further, aAI compounds were investigated for scaled-up production in a 14 L-bioreactor system. The results revealed a high yield (4200 U/mL) in a much shorter fermentation time (12 h) compared to fermentation in flasks. Bioactivity-guided purification resulted in the isolation of one major target compound, identified as hemi-pyocyanin (HPC) via gas chromatography-mass spectrometry and nuclear magnetic resonance. Its purity was analyzed by high-performance liquid chromatography. HPC demonstrated potent α-amylase inhibitory activity comparable to that of acarbose, a commercial antidiabetic drug. Notably, HPC was determined as a new aAI. The docking study indicated that HPC inhibits α-amylase by binding to amino acid Arg421 at the biding site on enzyme α-amylase with good binding energy (−9.3 kcal/mol) and creating two linkages of H-acceptors.     

绿鳍马面魨年龄和生长的初步研究

1.体长与椎体之间的关系呈正紧密直线相关。其关系式为:L=7.046R 49.590 r=0.938 2.用第一个椎骨的椎体作为观察和测定年轮的材料。年轮在透射光线下界于透明带和不透明带之间。其特征可分为以下三种类型:(1)单带型,(2)双带型,(3)多带型。 3.根据椎体边缘相对生长量的周年测定结果,证实该年轮系一年形成一次,时间为12月份至翌年5、6月份,主要的形成期是4～6月份。 4. 绿鳍马面鲀各龄鱼的平均体长和体重为:Ⅰ龄鱼:119.5毫米,44.5克;Ⅱ龄鱼:159.9毫米,70.9克;Ⅲ龄鱼:194.8毫米,136.9克;Ⅳ龄鱼:215.2毫米,190.8克;Ⅴ龄鱼;229.2毫米,231.3克;Ⅵ龄鱼:245.9毫米,283.5克。 5.体长和体重之间呈指数函数关系。关系式:L=41.324·W~(0.315) 6.从现有的标样观察和分析,绿鳍马面鲀的最高寿命为X龄。年龄组成比较简单,以Ⅲ、Ⅳ龄组占优势,Ⅵ龄以上各组数量极少。