基于改进的PSO进化神经计算进行苹果颜色快速分级

为克服在苹果颜色分级中存在的速度慢、误差大等缺点,基于再现群智能的粒子群进化算法和神经计算技术,提出了一种新颖、快速的智能分级方法,即首先通过计算机视觉技术获取苹果表面颜色的色度,并提取其特征;然后采用改进的带自适应惯性权值的粒子群优化算法训练神经网络结构,最后用训练好的神经网络进行苹果颜色分级。实际应用表明该方法切实可行且效果显著,不仅分级速度快,而且分级正确率高达98%以上。     

加强甜玉米鲜食期籽粒品质变化研究

研究加强甜玉米和普通玉米2种不同类型玉米鲜食期籽粒品质变化,以明确各品质变化的动态规律。试验采用不同基因型的玉米材料,测定果穗鲜食期可溶性总糖含量、水分含量、蛋白质含量和百粒鲜重,并进行相关分析。结果表明：鲜食期籽粒发育过程中加强甜玉米可溶性总糖含量和积累速度高于普通玉米;水分的下降速度加强甜玉米比普通玉米慢;蛋白质含量加强甜玉米略低于普通玉米,蛋白质的积累与籽粒鲜重的增加过程基本一致;鲜粒重积累速度加强甜玉米低于普通玉米;授粉13d和授粉28d加强甜玉米和普通玉米蛋白质含量和鲜粒重都相近。     

干法膨化宠物饲料技术参数关系的研究

采用双螺杆膨化机干法工艺对宠物全价粉状饲料进行膨化并制粒,研究所得产品的容重与淀粉糊化度、硬度指标之间的关系,以及设备参数和配方特性对颗粒饲料容重的影响。结果表明:容重与淀粉糊化度、硬度密切相关;设备参数与配方特性均对产品容重有极显著影响;通过容重的测定估测其熟度和硬度具有可行性;可以通过调节喂料速度和膨化玉米比例控制产品容重。     

Physiological response of flag leaf and yield formation of winter wheat under different spring restrictive irrigation regimes in the Haihe Plain,China

In order to identify the optimum period of spring water-restrictive irrigation for winter wheat(Triticum aestivum L.) in the Haihe Plain, China and elucidate its effects on flag leaf senescence and yield formation, field experiments were conducted at the Xinji Experimental Station of Hebei Agricultural University from 2016 to 2019 by using different irrigation regimes in spring, including the conventional regime involving two irrigation periods(control(CK), the 3-leaf unfolding stage and the anthesis stage) and a series of single, restrictive irrigation regimes(SRI) comprising irrigation at the 3-leaf unfolding stage(3 LI), 4 LI, 5 LI, and 6 LI. There are five major findings:(1) The senescence(determined by the green leaf area, GLA) in the 4 LI treatment occurred moderately earlier than that in CK, showed no significant difference with that in 5 LI and 6 LI, and occurred significantly later than that in 3 LI.(2) Compared with other SRI treatments, the GLA value and photosynthetic rate in 4 LI were 14.82 and 20.1% higher, respectively. Microstructural analysis of flag leaf also revealed that the mesophyll cells and chloroplasts were irregularly arranged under drought stress in 3 LI and 6 LI; however, drought stress had minimal negative effects on the microstructure in 4 LI and 5 LI.(3) Postponed irrigation in spring could significantly increase superoxide dismutase(SOD) and catalase(CAT) activities in the early stage of grain filling; however, these activities would subsequently decrease. Among the four SRI treatments, the overall enzyme activities were the highest in 4 LI, and the combined malondialdehyde(MDA) content in flag leaves in 4 LI and 5 LI was 14.5% lower on average than that in 3 LI and 6 LI.(4) The soluble sugar(SS) and proline(Pro) contents in 4 LI were the highest among the four SRI treatments; however, they were lower than those in CK. The abscisic acid(ABA) hormone content in 4 LI and 5 LI was lower than that in 3 LI and 6 LI, respectively, suggesting a smaller drought stress effect in 4 LI and 5 LI.(5) In two growing seasons, there was a larger number of spikes per unit area in 4 LI(i.e., 13.4% higher than that in 5 LI and 6 LI) and the 1 000-grain weight in 4 LI was the highest among the four SRI treatments(i.e., 6.0% higher than that in the other three SRI treatments). Therefore, a single restrictive irrigation regime at the 4-leaf unfolding stage is recommended to be effective in slowing down the senescence process of flag leaves and achieving high yield.     

优质水稻三系不育系金山A-4的选育及利用

以万利香与冈46B杂交,选择优质长粒型的单株建立株系,并与珍汕97A连续多代成对回交,育成柱头外露率高、不育性稳定、异交特性好、株叶态理想的优质不育系金山A-4。金山A-4配合力好,已配制出金山A-4/R401、金山A-4/蜀恢527等优质杂交稻组合。该不育系于2005年通过福建省科技厅科技成果鉴定。     

鹰爪虾形态性状和体重的通径分析及灰色关联分析

为探究鹰爪虾(Trachypenaeus curvirostirs)形态性状和体重的关系,本研究测定了体重(Y)及全长(X₁)、体长(X₂)、头胸甲长(X₃)、头胸甲宽(X₄)、头胸甲高(X₅)、第1腹节长(X₆)、第1腹节宽(X₇)、第1腹节高(X₈)、第6腹节长(X₉)、第6腹节宽(X₁₀)、第6腹节高(X₁₁)、尾节长(X₁₂)、尾扇长(X₁₃)13个形态性状,通过通径分析和灰色关联分析等方法研究了各性状之间的关系。结果显示,雌性鹰爪虾各生物学指标均大于雄性,雌、雄群体各性状之间均呈极显著正相关关系(P<0.01),体长(X₂)与体重的相关系数均最大(分别为0.972和0.969);通径分析和决定系数分析发现,雌、雄群体体长(X₂)对体重的直接影响和直接决定系数均最大(通径系数分别为0.443和0.519),雌、雄群体对体重间接作用最大的形态性状分别为第1腹节宽(X₇)(作用系数之和为0.750)和尾节长(X₁₂)(作用系数之和为0.887),雌性群体体长(X₂)和头胸甲高(X₅)的共同决定系数最大(0.167),雄性群体全长(X₁)和体长(X₂)的共同决定系数最大(0.248)。采用逐步回归法建立雌、雄群体形态性状与体重的多元回归方程分别为Y₁=–14.563+0.133X₂+0.374X₇+0.282X₅+0.225X₁₃(R₂=0.978)、Y₂=–7.947+0.092X₂+0.309X₄+0.203X₁₀+0.036X₁–0.087X₁₂(R₂=0.980)。雌性群体形态性状与体重的关联系数平均值在0.868~0.941之间,雄性群体的平均值在0.793~0.906之间,从同一形态性状来看,雌性群体与体重关联系数的平均值均大于雄性群体。雌、雄群体体长(X₂)与体重的关联度均为最高。通径分析结果和灰色关联分析结果并不完全相同,综合比较分析得出,在进行鹰爪虾选育时,雌、雄群体以体长(X₂)作为主要选择性状,雌性群体辅助选择头胸甲高(X₅)和第1腹节宽(X₇);雄性群体辅助选择头胸甲宽(X₄)和全长(X₁)。     

Bentonite-humic acid improves soil organic carbon,microbial biomass,enzyme activities and grain quality in a sandy soil cropped to maize (Zea mays L.) in a semi-arid region

A bentonite-humic acid(B-HA) mixture added to degraded soils may improve soil physical and hydraulic properties, due to effects such as improved soil structure and increased water and nutrient retention, but its effect on soil physicochemical and biological properties, and grain quality is largely unknown. The effect of B-HA, added at 30 Mg ha-1, was studied at 1,3, 5 and 7 years after its addition to a degraded sandy soil in a semi-arid region of China. The addition of B-HA significantly increa...     

Nitrogen application affects maize grain filling by regulating grain water relations

Grain water relations play an important role in grain filling in maize. The study aimed to gain a clear understanding of the changes in grain dry weight and water relations in maize grains by using hybrids with contrasting nitrogen efficiencies under differing nitrogen levels. The objectives were: 1) to understand the changes in dry matter and percent moisture content(MC) during grain development in response to different nitrogen application rates and 2) to determine whether nitrogen application...     

葡萄枝条中淀粉粒形态结构与抗寒力的关系

扫描电镜观察结果表明,越冬期间葡萄枝条组织细胞中淀粉粒的大小、积累数量和转化动态规律与抗寒力密切相关,主要表现为抗寒种类或品种的淀粉粒小,积累早而数量多,水解晚但速度快而较彻底;同一品种采用嫁接栽培可明显增加枝条中淀粉的积累数量,有利于枝芽成熟和越冬。