Utilizing Arachis cardenasii as a source of Cercospora leafspot resistance for peanut improvement

Summary Advanced generation 40-chromosome hybrids between A. hypogaea (2n=4x=40) and a wild diploid species. A. cardenasii were evaluated for early leafspot, Cercospora arachidicola resistance and agronomic potential. The objective of this investigation was to determine if early leafspot resistance derived from a wild species could be incorporated into the A. hypogaea genome. Interspecific hybrid selections were made and then compared in the field and greenhouse to susceptible cultivars and to A. hypogaea lines which are reported to be resistant to early leafspot. Significantly higher levels of resistance were found in five hybrid selections than in cultivated lines based on numbers of lesions per leaf. In a greenhouse study, several hybrid selections also had greatly reduced sporulation from lesions as compared to A. hypogaea. Several mechanisms of resistance are believed to be present. Although hybrid selections had small seeds and low yields as compared to A. hypogaea, a new and valuable source of early leafspot resistance derived from the species A. cardenasii is present.Paper no. 8814 of the journal series of the North Carolina Agricultural Research Service, Raleigh, NC 27695. This research was partially funded by AID-Peanut CRSP grant DAN-4048-G-SS-2065-00.     

导入外源DNA片段的花生根瘤菌高效基因工程菌株的构建

以柯斯质粒ｐＬＡＦＲ１为载体先构建快生型花生根瘤菌８５－７菌株总ＤＮＡ的基因文库。在协助质粒ｐＲＫ２０１３帮助下用此基因文库分别同菌株８５－７和另一株慢生型花生根瘤菌菌株Ｃ０２－５作三亲本杂交。转移接合子接种沙培条件下生长的花生，通过结瘤试验初筛选和复筛选，共筛选出３株工程菌ＨＮ１１，ＨＮ１２（以８５－７为受体）和ＨＮ１３（以Ｃ０２－５为受体）。其每植株根瘤的固氮酶活分别比出发菌株的提高３０２％（     

Effect of Mepiquat Chloride on Certain Physiological and Yield Characteristics of Groundnut (Arachis hypogaea L.)

Studies were carried out to understand the effect of mepiquat chloride (1,1–dimethyl piperidinium chloride) on some important physiological and yield characteristics of groundnut (Arachis hypogaea L.). Mepiquat chloride was sprayed at the concentration of 100, 125 and 150 ppm on 25 DAS (days after sowing), 35 DAS and 45 DAS respectively and compared with CCC (2–Chloro ethyl trimethyl ammonium chloride) which was sprayed at 100 ppm on 45 DAS. Response of the crop for both chemicals was almost similar but varying in magnitude. Among the treatments application of mepiquat chloride at 125 ppm on 35 DAS was found to be the best which reduced the shoot length and Leaf Area Index (LAI) and enhanced the root length and Crop Growth Rate (CGR). Yield characteristics such as Total Dry Matter Production (TDMP), number of flowers, and pod yield were also increased by the application of mepiquat chloride at 125 ppm on 35 DAS. This treatment recorded the maximum pod yield of 2611 Kg per hectare accounting for 24 % increase over CCC which is currently recommended to improve the yield of groundnut. The results of the present investigation indicated that foliar spray of mepiquat chloride at 125 ppm concentration on 35 DAS was optimum and improved the physiological efficiency of groundnut leading to higher yield.     

油菜“双龙”栽培防渍高产技术探讨

渍害是制约平原水网区春花产量的主要障碍因子。为解决渍害问题 ,近年来 ,桐乡市探索形成了油菜高畦阔沟“双龙”窄株栽培技术 ,并在桐乡市大面积推广 ,有效地防止了渍害 ,减轻菌核病 ,增产较为显著。一般烂冬年份比阔塄栽培增产 15 %以上 ,干旱年份增产 6%左右 ,正常年份增产 10 %～ 12 %。     

Pelleting or Priming Seed with Calcium Improves Groundnut Seedling Survival in Acid Soils

A growth chamber experiment and a field experiment were conducted to investigate the effects of pelleting or priming groundnut seed with calcium (Ca), either as calcium sulfate (CaSO₄), calcium chloride (CaCl₂), calcium nitrate [Ca(NO₃)₂], calcium carbonate (CaCO₃) or Calcimax on growth of groundnut seedlings in acid soils. In the growth chamber experiment, Ca-treated and non-treated groundnut seeds were planted in acid-washed sand and watered with a dilute nutrient solution of pH 4.0 or 5.5. In the field experiment, the seeds were planted in an acid sand clay loam of pH [potassium chloride (KCl)] 4.8. Generally, pelleting or priming the seed with a Ca compound significantly reduced seedling mortality. Also, pelleting groundnut seed with Ca enhanced plant growth. An additional effect of priming was earlier emergence. The most effective Ca compound was CaSO₄ among the priming treatments, whereas CaCO₃ was the most effective among the pelleting treatments to reduce seedling mortality.     

花生辐射突变体质量性状遗传

研究了用Gamma射线辐照花生产生的叶片白叶脉、叶较小突变体后代的遗传。结果表明，叶片白叶脉、叶片较小突变体后代分离出3种表现型：①所有性状与辐照前原品种相同；②所有性状与叶片白叶脉、叶较小突变体相同；③叶片白叶脉、叶极小、植株极矮、不结果。相应3种表现型的分离比例为1：2：1。认为白叶脉、叶片大小和植株高度是由同一基因位点控制的。高株对极矮株为显性，分离比例为3：1；白叶脉对黄叶脉是显性，分离比例为3:1；叶片大小是不完全显性效应，分离比例为1：2：1。叶片叶绿素含量与白叶脉无关，但与株高有关。     

花生田二代棉铃虫发生为害规律及其防治研究

第2代棉铃虫是危害花生最严重的世代，95％左右的卵产在花生中上部的嫩梢、嫩叶、花萼和茎基上，平均每株落卵19．6粒。在花生上的卵量和幼虫量与第1代蛾量密切相关，卵量（Y1）与第1代蛾量（X）关系式为：Y1＝－315．9＋1．7783X（n=6,r=0.8562)；幼虫量（Y2）与第1代蛾量（X）关系式为：Y2＝31．3＋0．134X（n=6,r=0.8652).在第2代棉铃早产卵初盛期应用B.t菌剂（含孢子100亿个／ml)200倍液喷雾3次，或1．8％齐螨素乳油675ml/hm^2兑水810kg喷雾2次，防效显著。     

巴蜀地区花生青枯病的分布及防治对策研究

自20世纪70年代后期以来,我们对巴蜀地区(原四川省)花生青枯病的分布及防治对策作了大量研究.发现了巴蜀地区有花生青枯病发生,发病面积30khm2左右、约占全国发病面积的10%;明确了四川盆地南部的酸性红、黄壤土区是主要病区,其次是江河沿岸的老冲积黄壤和新冲积潮沙区土,在碳酸盐紫色土上尚未发现花生青枯病;明确了汞制剂、铜制剂、托布津等杀菌剂,和一般性轮作、深耕等农艺措施,对花生青枯病无有效的防治作用,而选用抗病品种能有效地遏制花生青枯病蔓延为害,并筛选出一批抗病品种用于生产.     

Effects of malting on the milling performance and acceptability of bambara groundnut (Voandzeia subterranea Thouars) seeds and products

Germinated bambara groundnut was dried by three methods – oven-drying at 50 °C, in a solar drier at 38–42 °C, and sun drying at 28 ± 2 °C. The samples were milled into flour, and made into okpa, a steamed gel. Flour yield increased only in oven-dried malts. The quality of the okpa based on appearance and taste decreased with malting time; solar drying resulted in the poorest product because of its dark color.