Karanj protein isolate prepared from karanj seed cake: Effect on growth,body composition and physiometabolic responses in Labeo rohita fingerlings

A protein isolate was prepared from karanj seed (KPI) with 921.2 g protein/kg seed, which contained a negligible amount of anti‐nutritional factors and a balanced amino acid composition, especially rich in methionine. For 60‐day feeding trial, five isonitrogenous (300 g/kg CP) and isocaloric (15 MJ DE/kg) diets were formulated by replacing soybean protein isolate (SPI) on protein equivalent basis, KPI‐0 (control, 0 g/kg KPI); KPI‐25 (replacing 250 g/kg SPI protein with KPI); KPI‐50 (replacing 500 g/kg SPI protein with KPI); KPI‐75 (replacing 750 g/kg SPI protein with KPI) and KPI‐100 (replacing 1,000 g/kg SPI protein with KPI) for the feeding of L. rohita. The weight gain percentage, specific growth rate, feed conversion ratio and protein efficiency ratio were not significantly (p > .05) varied among the KPI fed and control groups. A significantly higher hepatosomatic index was recorded in the control and KPI‐25 groups compared with other groups. The whole‐body compositions, except ether extract, did not differ significantly (p > .05) among the groups. Digestive (amylase, protease, lipase and alkaline phosphatase) and metabolic enzyme activities (hexokinase, transaminases and lactate dehydrogenase) and glycogen stores were not significantly affected, whereas intestinal alkaline phosphatase differed significantly (p < .05). The RNA–DNA ratio was significantly (p < .05) higher in the KPI‐75 group. Thus, the study revealed that KPI can completely replace SPI protein at 191 g/kg inclusion level in the diets of L. rohita fingerlings.     

Partial replacement of fishmeal with corn gluten meal,pea protein isolate and their mixture in diet of black sea bream (Acanthopagrus schlegelii) juveniles: Effects on growth performance,feed utilization and haematological parameters

Corn gluten meal (CGM), pea protein isolate (PPI) and their mixture (CPP, 1:1 ratio) were evaluated as fishmeal (FM) alternatives in black sea bream (Acanthopagrus schlegelii) juveniles (9.02 ± 0.12 g). A FM diet was designed as control, and other six diets had 20% and 40% FM protein replaced by CGM, PPI and CPP, respectively, with the supplementation of crystalline methionine, arginine and lysine. After the 8‐week feeding trial, significantly lower weight gain was found in fish fed the 40% CGM diet (p < .05), whereas other treatments had no statistical difference (p > .05). The values of feed efficiency ratio and feed intake, as well as proximate compositions of muscle and whole body, were not significantly influenced in all treatments. Apparent digestibility coefficients (ADCs) of dry matter, crude protein, threonine, valine, methionine, isoleucine, leucine, phenylalanine and lysine were significantly influenced by protein source. Fish fed the 40% CGM diet had significantly higher content of essential amino acid in muscle than that of the 20% PPI diet. Fish fed the 40% CGM diet had significantly lower content of serum cholesterol than other treatments (p < .05). Elevated serum superoxide dismutase activity was found in fish fed the 40% plant protein diets. In conclusion, between 20% and 40% FM protein could be replaced by CGM, while about 40% FM protein derived from PPI and CPP could be applied in black sea bream.     

城乡共建田园综合体——城市近郊乡村用地规划研究

:在城市快速扩张的冲击下,城市乡村之间整体呈现出割裂关系,不利于社会的健康发展,城市边缘区乡村用地地位于城市农村的腹地,是未来城乡融合发展的桥梁纽带。随着乡村振兴战略的提出,以产业结构转型为代表的田园综合体为未来乡村发展提供了新的思路,本文探讨了在城乡融合背景下城市近郊乡村地区建设田园综合体的可行性、建设原则与建设思路。     

根癌农杆菌介导的稻瘟病菌近等菌系的构建与初步应用*

 利用根癌农杆菌C58C1介导转化1株致病力极弱的野生型稻瘟病菌菌株CY2,成功地获得3000多个转化子,混合接种于携带25个不同抗病单基因的水稻近等基因系上,获得4株单胞致病突变体;继代培养和PCR检测表明,这些突变体均为T-DNA插入CY2的后代,而非自发突变或外源菌株污染。将4株突变体与实验室已保存的20株致病突变体分别回接水稻近等基因系,推断其携带的致病基因类型,结果表明突变体分别针对13个抗性单基因的18个单基因系发生了突变,其中针对Pi-a,Pik-s,Pi-sh单基因系表现出较高的侵染频率。由于这些突变体均来自同一个菌株,仅致病性存在差异,属于近等菌系,利用其分析出102个水稻品种中的34个品种的抗病基因组成,其中,抗病基因Pik-s,Pi-a,Pi-sh,Pi-19(t)分布频率较高,分别达70.59%,61.76%,52.94%和44.12%,且带有这类基因的糯稻品种多于杂交水稻。     

红茶感官品质及成分近红外光谱快速检测模型建立

以在发酵过程中小叶种工夫红茶为研究对象,分别建立了基于近红外光谱检测技术的感官品质评分和理化品质指标(茶黄素、茶红素、茶褐素、儿茶素和酚氨比)的定量分析模型。在模型建立过程中,探讨了特征变量优选方法对预测模型的影响。首先,对获取的近红外光谱数据进行标准正态变量变换法(standard normal Z transformation,SNV)预处理,进而采用联合区间偏最小二乘回归(synergy interval PLS,Si-PLS)、随机蛙跳算法(shuffled frog leaping algorithm,SFLA)、竞争性自适应权重取样法(competitiveadaptivereweightedsampling,CARS)和连续投影(successive projections algorithm,SPA),筛选出各品质指标的最优特征波长变量;最后基于优选波长分别建立各发酵品质指标的偏最小二乘法(partial least squares regression,PLS)线性预测模型和支持向量机(support vector regression,SVR)非线性预测模型。模型结果比较表明,Si、CARS、SFLA和SPA等变量筛选方法可有效压缩变量,以及进一步提高模型精度。非线性模型的预测均方根误差值(root-mean-square error of prediction,RMSEP)均明显小于PLS模型,相关性系数(correlation coefficient,R)和相对分析误差(relative percent deviation,RPD)均高于PLS模型。对于红茶发酵品质的检测上,非线性模型性能优于线性模型。感官品质、茶褐素和儿茶素的最优变量SVR预测模型的RPD值分别为3.923、3.234和5.462,酚氨比和茶红素模型的RPD值分别为2.815和2.223。除茶黄素的评价模型外(RPD为1.77),基于最优特征波长的各品质指标SVR模型的RPD值均大于2,表明模型具有极好的预测性能。研究结果为实现工夫红茶发酵品质的近红外光谱快速检测的实际应用奠定理论基础。     

Detection of Frozen-Thawed Cycles for Frozen Tilapia (Oreochromis) Fillets Using Near Infrared Spectroscopy

Due to the ambient temperature fluctuation during the process of storage, transportation, and sale, frozen fillets may go through frozen-thawed cycles that result in quality changes. In order to detect the frozen-thawed cycles in frozen tilapia fillets, near infrared spectroscopy was applied. The thawing loss, cooking loss, moisture content, total volatile basic nitrogen, and texture profile of fillets in seven frozen-thawed cycles were analyzed to reflect the change of quality. A total of 60 fillets were used to collect the spectra on both dorsal and belly flesh in frozen and thawed state from the first to the seventh cycle. The results showed that there is a better discrimination among the once and the repeated frozen-thawed samples in the frozen state than the thawed state. Frozen samples were still conducive to the differentiation and had higher classification accuracy, ranging from 80% to 93.33%. Dorsal flesh was more beneficial for the differentiation than belly flesh and had the highest accuracy, ranging from 86.67% to 93.33% in the frozen state. These results showed that the nondestructive and fast detection of repeated frozen-thawed cycles in frozen tilapia fillets can be accomplished by near infrared spectroscopy, which has enormous potential for practical application.     

小麦条锈病菌新菌系G22-9(CYR34)和G22-14流行趋势预测

为预测小麦条锈病菌新菌系G22-9(CYR34)和G22-14的未来流行趋势,科学指导小麦抗病育种及条锈病治理,采用常规鉴定法于2009—2016年对甘肃省2 330份小麦条锈病菌标样进行了生理小种鉴定及消长动态监测,并对G22-9(CYR34)和G22-14的致病性及寄生适合度进行了测定。结果发现:新菌系G22-9(CYR34)和G22-14在甘肃省的出现频率加快,已从2009年的0分别上升到2016年的34.85%和6.43%,其中G22-9(CYR34)已发展为甘肃省第1位流行生理小种。与主流生理小种CYR32和CYR33相比较,G22-9(CYR34)和G22-14具有毒性谱宽、致病力强、寄生适合度高、哺育品种多等特点。建议在甘肃省特别是小麦条锈病常发易变区的陇南麦区,针对新菌系的出现,及时调整小麦品种布局及育种目标,以持续控制条锈病的发生流行。     

机器学习在近红外光谱法判别鲍鱼品种研究中的应用

为解决市场上鲍鱼产品缺乏科学分类方法的问题,利用近红外光谱分析技术结合机器学习方法对鲍鱼快速分类进行研究,使用MicroNIRTM1700便携式近红外光谱仪采集3种鲍鱼,即绿盘鲍(25只)、红壳鲍(31只)、皱纹盘鲍(35只)的光谱数据,采用CART算法建立鲍鱼分类决策树模型,以模型对测试集样本的预测准确率衡量决策树模型优劣,分裂策略为在每个节点处选择Gini不纯度最大的方式进行分裂,通过交叉验证控制决策树深度。结果表明,对训练集180条光谱建立模型,采用5折交叉验证,模型准确率为90.00%,对测试集93条光谱的预测准确率为90.32%。本研究方法可以很好地区分绿盘鲍、红壳鲍和皱纹盘鲍,满足鲍鱼现场快速分类的需求。     

甜玉米葡萄糖、果糖和蔗糖含量近红外反射光谱模型构建

甜玉米是世界上重要的果蔬两用型作物之一。建立快速、无损检测甜玉米糖分含量的方法,对于甜玉米品质育种工作中的材料鉴定、筛选具有重要意义。选取了104份糖分含量变幅较大的甜玉米材料进行了近红外光谱分析,结合酶法测量的化学值,利用偏最小二乘法以及不同光谱处理和数学处理相结合,对全光谱波段进行了化学计量学的分析统计,构建了葡萄糖、果糖和蔗糖含量的近红外光谱定标模型。用外部验证样品集进行验证,对所建模型的实际预测能力进行检验。结果表明：最优光谱处理方式葡萄糖为加权多元散射校正,果糖和蔗糖的为标准正常化加去散射处理;最优的导数处理葡萄糖为2阶导数,果糖和蔗糖的为1阶和3阶导数。葡萄糖、果糖和蔗糖定标模型的交叉验证相关系数分别为0.646、0.645、0.820,交叉验证标准偏差分别为0.321、0.275、1.508;外部验证集葡萄糖、果糖和蔗糖的预测相关系数分别为0.593、0.780、0.891,表明所建立的果糖和蔗糖预测模型具有较好的预测性,可应用于甜玉米种质资源筛选,而葡萄糖模型的预测性较差,需继续完善。     

基于可见/近红外光谱的黄河口区土壤盐分及其主要离子的定量分析

【目的】定量、准确地监测盐渍土,对其防治和农业可持续发展至关重要,论文旨在明确黄河口区土壤盐分及其主要离子的特征光谱,建立适用于该区域的土壤盐渍化定量分析模型,提高其定量分析的精度和稳定性。【方法】首先以山东省垦利县为研究区,于2014年10月5—9日野外采集代表性土样96个,对土样风干后,采用土壤化学分析方法室内分析盐分及其主要离子(Cl~-、Na~+、Ca~(2+))含量,并采用美国ASD Fieldspec 3光谱仪测定土样可见/近红外高光谱数据,对光谱反射率进行去噪、一阶导数变换等预处理;然后基于盐分及其主要离子不同含量的样本光谱分析盐分及其主要离子的光谱响应,在此基础上,对样本的土壤盐分及其主要离子含量与反射率的一阶导数光谱进行逐波段的相关分析,按照相关系数高且显著的原则,选取各自的敏感波段,再根据敏感波段的交叉情况选取集中波段为特征波段,进而选取特征波段中具有极值相关系数的波段作为显著特征波段,综合确定表征土壤盐分及其主要离子(Cl~-、Na~+、Ca~(2+))的特征光谱;最后分别采用多元线性回归(multiple linear regression,MLR)、支持向量机(support vector machine,SVM)和随机森林(random forest,RF)方法构建土壤盐分及其主要离子的定量高光谱分析模型。【结果】研究区土壤盐分及其主要离子(Cl~-、Na~+、Ca~(2+))含量的光谱曲线形状和走势整体一致;土壤盐分及其主要离子(Cl~-、Na~+、Ca~(2+))的光谱响应谱区为1 320—1 495、1 790—1 920、2 120—2 290 nm;基于相关分析的土壤盐分及其主要离子的敏感谱区为1 490—1 520、1 890—1 930nm;最后综合光谱响应及相关分析确定土壤盐分及其主要离子的特征波段为1 493、1 801、1 911和2 289 nm,显著特征波段为1 493和1 911 nm。模型结果显示基于2个显著特征波段反射率一阶导数的模型精度均与4个特征波段的模型精度相当,表明显著特征光谱作为盐分及其主要离子的特征光谱进行其定量分析的有效性。比较3种建模方法,RF模型的预测效果最好,SVM模型次之,而MLR模型精度最低;对于盐分、Cl~-和Na~+,3种方法构建的模型均可有效地用于其定量分析,精度较高且稳定,然而Ca~(2+)预测精度还有待提高。通过综合比较分析,基于显著特征波段(1 493和1 911 nm)反射率一阶导数构建的随机森林(RF)模型对盐分、Cl~-和Na~+均具有较好的估测精度和稳定性,也可用于Ca~(2+)的定量估测。【结论】基于光谱响应及相关分析综合确定盐分及其主要离子的显著特征光谱(1 493和1 911 nm反射率一阶导数),进而采用随机森林方法构建盐分及其主要离子的定量估测模型,适用于黄河口区土壤盐渍化信息的有效提取。