Estimating starch availability and protein degradation of steam-flaked and reconstituted sorghum grain through a gas production technique

Five steam-flaked sorghum grain (SFSG) samples with bulk densities of 476, 412, 347, 309 and 283 g/liter made by adjusting tension between mill rollers and three reconstituted sorghum grain (RSG) samples with reconstitution times of 10, 20 and 30 d and a control sample were analyzed for gas production kinetics (rumen liquor fermentation) and enzymatic glucose release (amyloglucosidase). Protein degradation was estimated from 6-h gas production and residual ammonia in the liquid. Gas production followed first-order kinetics (r2 greater than .98; P less than .01) and was used to describe rate and extent of digestion kinetics. Rate of gas production increased as processing degree increased. The magnitude of increase in gas production, however, was much less for RSG than for SFSG. Linear relationships were observed between enzymatic glucose release and the gas production rate constant k as well as gas production at 4,6 and 8 h (r2 greater than .98; P less than .01). Protein degradation decreased with processing degree of SFSG but increased with reconstitution time. A technique based on 6-h gas production and residual ammonia in the liquid is proposed to estimate both ruminal starch availability and ruminal protein degradability for processed sorghum grain.     

云南德宏地区春砂仁传粉蜜蜂的研究

在德宏地区,对春砂仁产量的形成起主要作用的蜜蜂有彩带蜂、隧蜂、中华蜜蜂、熊蜂、小蜜蜂、排蜂。其中彩带蜂、熊蜂、排蜂的有效传粉率高,小蜜蜂、隧蜂、中华蜜蜂次之。它们的数量、分布受生态环境、气候条件、砂仁种植面积等的影响,呈动态变化。春砂仁的自然授粉由几种蜜蜂共同进行,蜂多,传粉机率则高。全天蜂次与采花次,采集高峰时间每小时平均蜂次与传粉率,均呈极显著正相关。应用直线回归方程,可推算春砂仁花期是否具备足够传粉动力。观察结果表明,传粉率达90％以上的指标,是每平方米面积内当天开花50～70朵,采集高峰时间每小时出现钻花采集的蜜蜂20～30次。云南野生中华蜜蜂适应性强,生态类型多,定向筛选、繁育传粉效果好的蜂群,则可望解决初花期或缺少传粉昆虫地区的春砂仁授粉问题。     

宁夏利通区奶牛干奶期钙、磷盈亏状况调查

在对宁夏吴忠市利通区 4个奶牛场和 10户养牛户进行奶牛干奶期钙、磷营养状况调查中 ,分别测定了饲料中钙、磷含量 ,奶牛干奶期血清中钙、磷、羟脯氨酸、碱性磷酸酶、甲状旁腺素、降钙素含量。结果表明 :奶牛饲料中钙含量除小户基本正常 ,大户磷含量明显偏低 ,钙、磷比例失衡 ;散户日粮钙不足 ,小户钙、磷盈亏状况良好。血钙与碱性磷酸酶呈中度负相关 ,与甲状旁腺素呈中度正相关 ,相关系数分别为 - 0 .48(P<0 .0 42 )和 0 .48(P<0 .0 44 )。降钙素处于正常水平范围之内 ,平均值为 7.80± 8.16 pmol/l,95 %的置信区间为 3.75～ 11.86 pmol/l     

杂交稻蓄留再生稻的增产技术分析

在大面积生产调查基础上，对杂交稻蓄留再生稻的产量构成因素有效穗、穗实粒数和千粒重与产量进行了通径分析。结果表明有效穗对再生稻产量起主导作用，其次是穗实粒数。同时，结合研究分析了进一步提高穗数和结实率的途径。最后提出了再生稻每公顷２．２５～３．００ｔ的穗粒结构和技术要点，以供指导大面积再生稻生产     

重组病毒C731的蛋白质和核酸分析及免疫原性的初步测定

使用密度梯度离心提纯FMDV、EV和重病毒C731,3种病毒分别位于不同的蔗糖密度区域。用高效液相层析法(HPLC)分析3种病毒的结构蛋白和病毒RNA的核酸酶水解片段,证明C731与FMDV、EV在蛋白RNA和结构上存在明显差异。对3种病毒蛋白的氨基酸成分和含量作了分析。接种实验动物证明,C731可寄生于动物的肠道,能使动物产生较高滴度的抗FMDV和EV抗体。     

盐酸环丙沙星在雏鸡体内蓄积毒性的研究

对盐酸环丙沙星在雏鸡体内的急性毒性进行了研究。结果ＬＤ５０为２８６２．８６ｍｇ／ｋｇ体重；蓄积系数Ｋ≥５．３，此时无一只雏鸡死亡，为轻度蓄积或基本无蓄积；雏鸡对本品产生明显耐受性，应用安全可靠。     

景宁县经济林生产现状及发展方向

随林种结构的调整，景宁县近几年来兴建经济林基地的发展速度很快，这与县林业局营林公司和县农业综合开发公司两家龙头企业推动作用有关，同时揭示了规模不大管理粗放、没有发挥地方特色优势缺乏竞争力、技术含量低等问题，提出了要搞好整体规划，努力挖掘地方名优特产、选准品种实行良种化、在规模化基础上突出主栽品要形成区域化、走种养加工一条龙、贸工农一体化、农科教相结合的路子。     

Simple protoplast isolation system for gene expression and protein interaction studies in pineapple (Ananas comosus L.)

Background

Seed viability monitoring is very important in ex situ germplasm preservation to detect germplasm deterioration. This requires seed-, time- and labor- saving methods with high precision to assess seed germination as viability. Although the current non-invasive, rapid, sensing methods (NRSs) are time- and labor-saving, they lack the precision and simplicity which are the virtues of traditional germination. Moreover, they consume a considerable amount of seeds to adjust sensed signals to germination percentage, which disregards the seed-saving objective. This becomes particularly severe for rare or endangered species whose seeds are already scarce. Here we propose a new method that is precise, low-invasive, simple, and quick, which involves analyzing the pattern of dehiscence (seed coat rupture), followed by embryonic protrusion.

Results

Dehiscence proved simple to identify. After the trial of 20 treatments from 3 rice varieties, we recognized that dehiscence percentage at the 48th hour of germination (D(48)) correlates significantly with germination rate for tested seed lots. In addition, we found that the final germination percentage corresponded to D(48) plus 5. More than 70% of the seeds survived post-dehiscence desiccation for storage. Hydrogen peroxide (1 mM) as the solution for imbibition could further improve the survival. The method also worked quicker than tetrazolium which is honored as a fast, traditional method, in detecting less vigorous but viable seeds.

Conclusion

We demonstrated the comprehensive virtues of dehiscence method in assessing rice seed: it is more precise and easier to use than NRSs and is faster and more seed-saving than traditional methods. We anticipate modifications including artificial intelligence to extend our method to increasingly diverse circumstances and species.

     

尼氏钝绥螨抗有机磷自然种群的研究

我们从1989年以来调查柑园中植绥螨自然种群抗药性,一年来调查研究三个地方的四个种群,发现江西赣州的尼氏钝绥螨自然种群对亚胺硫磷、水胺硫磷和乐果的 LC50分别达1299.6ppm、875.3ppm 和529.2ppm,比尼氏钝绥螨敏感种群分别高59.1倍,31.3倍和21.3倍。赣州种群的酯酶同工酶电泳分析发现抗药性的 E_2带特别宽且色深,与毒性测定结果相应。且在赣州当地果园的虫口密度相当高,平均达0.36头/叶,比同期桔全爪螨的0.28头/叶还高。赣州种群与广州种群能自然交配繁殖后代,说明尚未达到种和亚种级分化,可用助迁手段来使其他地方尼氏钝绥螨提高抗药性。     

西方盲走螨在兰州地区苹果园定殖和防治叶螨效果的观察研究

1988～1989年,在兰州市农科所和榆中县园艺场对1983年以来释放过西方盲走螨的苹果园及其周围进行了调查。结果表明,该螨已在兰州地区自然越冬,建立种群。1983～1987年先后重复释放面积为9亩,1988年自然发生面积21亩,1989年达41亩,对李始叶螨发挥良好的控制效果,年施药次数可减少2～3次。在地下土缝、地表覆盖物和枯枝落叶丛中越冬的西方盲走螨,是兰州地区自然发生的主要虫源。西方盲走螨越冬成功与否,与越冬前和出蛰期的食料条件,及其活动期使用化学药剂的影响密切相关。