不同熟期菜用大豆籽粒生化物质积累规律及适宜采摘期研究

选用36个菜用大豆品种(早熟品种8个,中熟品种14个,晚熟品种14个),在其荚果发育过程中分期取样,对不同时期鲜豆粒的蛋白质、游离氨基酸、脂肪、淀粉和可溶性糖、Vc等生化物质的含量及百荚鲜重进行了系统测定,分析其积累规律,进而确定不同熟期菜用大豆品种的适宜采收期.结果表明:早熟品种的适宜采摘期为花后35 d左右,中熟品种为40 d左右,晚熟品种为45 d左右.     

番石榴ISSR-PCR最适反应体系的建立与验证

为更好的将ISSR标记应用于番石榴种质研究,本研究以“维邦2号”番石榴DNA为筛选体系试验材料,采用单因子试验对ISSR反应中Mg2+浓度、dNTPs浓度、引物浓度、Taq酶浓度、DNA浓度进行了优化。实验结果表明,番石榴20µl最适反应体系为：2.0µl 10×Buffer,1.0mmol/L Mg2+,0.25mmol/L dNTPs,0.8mmol/L引物,0.2U Taq酶,10ng的DNA。利用该反应体系,选用引物UBC810对9份番石榴种质进行PCR反应,再选取“南宁本地番石榴实生2号”DNA作为模板对8条ISSR引物进行PCR反应,对所确立的扩增体系进行验证。结果显示扩增产物条带多态性丰富,且特异性强、重复性好,表明本研究所确定的反应体系适用于番石榴的ISSR分子标记。     

Yield and growth characteristics for cotton under various irrigation regimes on sandy soil

Over-watering cotton wastes a valuable and scarce resource; it can also lead to rank growth, nutrient leaching, and contaminated groundwater. Since under-watering can decrease yields, the question becomes one of finding the optimum application regime. An irrigation experiment was set up to apply water at six different application rates, ranging from 33% to 144% of normal, with hopes of identifying the regime that produces maximum yield. Two cultivars, Acala Maxxa and Acala PhytoGen-72 (Gossypium hirsutum L.), were planted on sandy soil and irrigated daily with a highly efficient subsurface drip irrigation system for four seasons. The results showed that on the average there was no significant difference in the yield of the two cultivars and there was no significant difference in the yield for the three wettest treatments. The driest of the three wettest treatments, treatment 4, was a critical point on the water production function curve. It represented the least amount of water applied that still produced essentially maximum yield, and it had the highest water use efficiency. This critical level of water application during mid-season was found to be, on the average, 95% of Class A pan evaporation; it corresponded to a total seasonal application of 654 mm of water. Any application less than this critical level decreased yields. Reducing the water application by 5% below the critical level caused about a 4.6% reduction in yield. The critical level produced a soil moisture level that remained nearly constant throughout the season. The final plant height was closely related to the depth of water applied, with the wettest treatment producing plant heights of 2.0 m, and the driest treatment producing plant heights of 0.6 m. At the extremes of the water application rates there were some small differences in the early-season growth rate of the plants, but the main cause of differences in final plant height was the date of cutout (cessation of main stem node production). The length of season for the driest treatment was about 4 weeks shorter than for the wettest treatment on both cultivars. Results showed that deficit irrigation of cotton on sandy soil can greatly reduce yield, and the practice should probably be avoided.     

内燃机径向滑动轴承的进化设计法

采用Matlab语言,分别运用改进型粒子群算法和基本粒子群算法,在最大限度满足液体动力润滑径向滑动轴承的承载量系数值和达到滑动轴承承载能力的条件下,对内燃机径向滑动轴承进行了优化设计。计算机仿真结果表明：采用改进型粒子群算法的轴承孔直径、轴颈直径、轴承宽度、承载量系数等优化参数效果最好,符合实际工艺要求,且滑动轴承承载能力最强。改进型粒子群算法优化结果明显优于基本粒子群算法的优化结果,表明改进型粒子群算法应用于内燃机问题的优化求解切实可行。     

微灌毛管水力解析及优化设计的遗传算法研究

根据微灌毛管水力学特性,应用遗传算法理论和方法,提出微灌毛管水力解析及设计的新方法,建立了两种典型毛管水力解析和设计的遗传算法模型及求解方法,该方法可适用于非均匀坡度、不等间距及不等流量灌水器的毛管解析和设计。模拟计算结果表明,该方法具有较高的求解效率和计算精度。     

屯留县旱农实验区农林牧优化结构研究

调整农林牧结构是干旱、半干旱地区农业走出低谷、摆脱困境的战略措施。本文通过对实验区资源评价、农业生产的历史考察和现状辨识。明确了农业发展的优势和主要问题,运用线性规划模型确立了多目标兼顾的农林牧优化结构。     

响应面试验优化霍山石斛原球茎增殖培养基

为可持续开发霍山石斛资源,采用响应面法优化霍山石斛原球茎增殖培养基。在单因素试验基础上,根据Box Behnken试验设计原理,采用三因素三水平的响应面分析法,以增殖率为响应值进行回归分析。结果表明,萘乙酸（简称NAA）及6 苄氨基嘌呤（简称6 BA）浓度对增殖率影响最为显著,6 BA与马铃薯两者间交互作用显著,适宜的NAA、6 BA及马铃薯浓度分别为0.05 mg·L-1、0.70 mg·L-1和185 g·L-1,此时增殖率为2 989.82%±205.55%,与模型预测值基本符合。响应面法优化霍山石斛原球茎增殖培养基切实可行。     

矿区废弃地植被重建技术

总结了安太堡露天煤矿十余年来植被重建技术 ,具体包括种植密度与林草混交、直播与移栽、扦插与管理、植物的优化配置等 ,并对每种技术作了简要评价     

玉米瘤黑粉病空间分布型研究

对玉米瘤黑粉病空间分布型进行了研究,结果表明:玉米瘤黑粉病在病株率低于4%的条件下,空间分布型基本为随机分布;病株率在10%左右,空间分布型仍为随机分布,但有均匀分布趋势。根据平均拥挤度和平均密度关系回归方程,得到病害在不同发病程度下的理论抽样数:若想获得一般精确的调查结果,在病株率达到1%左右时,大约需要调查285个样本;在病株率达到5%左右时,大约需要调查135个样本;在病株率达到10%以上时,大约需要调查115个样本。     

施肥对饲草高粱生长及营养品质的影响

研究施用氮、磷,钾肥对饲草高粱生长及营养品质动态的影响结果表明,氮肥、磷肥和钾肥配合施用可大幅提高饲草高粱生物产量,增加饲草高粱植株粗蛋白质、粗纤维和粗脂肪的单位面积产出量;氮素是影响高粱生物产量的首要养分因素,其次为磷素,第三是钾素;饲草高粱植株高度以及粗蛋白质、粗纤维和粗脂肪含量的变化规律,主要取决于品种特性;施肥主要通过影响饲草高粱生物产量,对饲草高粱植株粗蛋白质、粗纤维和粗脂肪的单位面积产出量产生作用.从饲草高粱的生物产量和品质综合考虑,确定饲草高粱的适宜收割期,以开花末期至成熟中期之间为宜,过早收割饲草高粱生物产量较低,过晚收割则饲草高粱生物产量较低且品质变劣.