无人机遥感及深度学习在油菜冻害识别中的应用研究

气象灾害是影响我国农作物产量及农业可持续发展的重要因素,低温冻害导致油菜生长发育迟缓和大幅度减产.便捷、精准地识别和评估油菜冻害不仅为精准农田管理提供依据而且对培育抗冻品种有重要意义.本研究借助低空无人机遥感技术,用大疆精灵无人机Phantom 4 Pro V2.0,搭载2000万像素RGB相机,对生长88天正处于越冬...     

利用激光光源的荧光成像系统高通量计数大豆孢囊线虫褐化孢囊

高效准确的孢囊计数方法对大豆孢囊线虫研究具有重要意义。为改善普通的荧光成像系统激发光能量偏低,褐化孢囊被激发的荧光减弱,难以清晰成像且计数效果欠佳的问题,本研究改用激光为激发光源,在470nm的激发波长和535nm的发射波长组合或532nm激发波长和620nm发射波长组合条件下,褐化孢囊也可得到对比度高且清晰的图片,配合使用自动计数软件,可以准确高效地进行孢囊计数。     

Screening and identification of soybean varieties with high phosphorus efficiency at seedling stage

In order to simplify the workload and find a reliable method for screening soybeans with different phosphorus(P)efficiencies,47 soybean varieties were screened from 90 varieties according to yield under normal phosphorus,and 10 indicators including root phenotype,phosphorus utilization efficiency at the seedling stage and yield were measured.Through single-index cluster analysis,the performance value and relative value of the abovementioned indexes under low-phosphorus conditions were analyzed,and then,the combined indexes were analyzed by principal components method.The membership function method and the cluster analysis method was used to calculate and analyze the comprehensive score value.Three indexes of root P utilization efficiency(X₁),relative value of root P utilization efficiency(X₂),and root volume(X₃)under low P at the seedling stage were selected as the most consistent with the yield screening results under low P condition,and the mathematical model of the comprehensive score value was obtained:D=1.218X₁t 0.320X₂t 0.007X₃-0.664(P=0.000,R²=1.000).The comprehensive score can screen and identify the P efficiency of soybeans with fewer indexes in the early growth stages,which provides a more rapid and reliable mathematical model for screening and identifying a larger number of germplasm resources for P efficiency.     

The assessment of feto-maternal hemorrhage in an artificial model using anti-D and anti-fetal hemoglobin antibody by flow cytometry

BACKGROUND: When fetal red cells enter the maternal circulation from placenta, an event would be happened that is described as feto-maternal hemorrhage (FMH). This life-threatening condition could be detected by using RBC antigens (surface antigens and intracellular antigens). Therefore, the measurement of fetal RBC in an artificial model would be useful to calculate FMH and consequently the dosage of Rhogam for prophylaxis. The aim of the present study was to evaluate FMH in an artificial mixture model. METHODS: A series of 40 artificial specimens were prepared consisting of Rh(D) negative adult blood (non-immunized) spiked with varying amounts of Rh(D) positive cord blood from mothers between 20-30 years old in Shahid Beheshti Hospital, Tehran, Iran. Monoclonal anti-D and anti-HbF (fetal hemoglobin) were used for detection of fetal RBC in artificial mixture sample modeling. RESULTS: This study showed that the percentage of fetal cells in artificial sample for anti-D antigen is in ranges of 0.28%-0.32% for a 0.25% dilution mixture, and 1.3%-2.05% for the mixture with dilution 2%. In addition, the ranges of data for anti-HbF staining was obtained 0.2%-0.34% for the 0.25% dilution sample, and the ranges of 1.04-1.8% for the 2% dilution. The regression analysis indicated that the correlation of anti-D assessment with expected standard method was r2 = 0.9672 and anti-HbF assessment was r2 = 0.8842. CONCLUSION: Although both molecule targets could be used for detection of fetal RBC, in this model, anti-D staining was more accurate than anti-HbF staining. However, since anti-D can not be utilized for low-density or weak phenotype and other incompatibility, the anti-HbF labeling could be used for all FMH.     

Estimation of spectral responses and chlorophyll based on growth stage effects explored by machine learning methods

Estimation of leaf chlorophyll content(LCC) by proximal sensing is an important tool for photosynthesis evaluation in high-throughput phenotyping. The temporal variability of crop biochemical properties and canopy structure across different growth stages has great impacts on wheat LCC estimation, known as growth stage effects. It will result in the heterogeneity of crop canopy at different growth stages, which would mask subtle spectral response of biochemistry variations. This study aims to exp...     

Phyllosticta species on citrus: Risk estimation of resistance to QoI fungicides and identification of species with cytochrome b gene sequences

Isolates of three fungal species associated with citrus, Phyllosticta citricarpa, Phyllosticta citriasiana and Phyllosticta capitalensis, collected from different citrus growing countries of the world, were investigated for their sensitivities to the QoI fungicides pyraclostrobin and azoxystrobin. Isolates were highly sensitive in microtiter tests and EC₅₀ values were in narrow ranges, which indicate no acquired adaptation to QoIs. The resistance risk of P. citricarpa to QoIs is considered low since an intron was found immediately after codon 143 in the cytochrome b gene. The presence of an intron is known to reduce the risk of the G143A mutation, the mutation which causes QoI resistance with high resistance factors. The other two species had no intron and therefore are considered having a higher resistance risk. Impact of these two species is rather low, since P. citriasiana is restricted in its regional and host distribution and P. capitalensis is non-pathogenic. Furthermore, the development of a rapid and reliable assay for species detection and identification was made possible based on an analysis of the cytochrome b gene.     

A deep learning-integrated phenotyping pipeline for vascular bundle phenotypes and its application in evaluating sap flow in the maize stem

Plant vascular bundles are responsible for water and material transportation, and their quantitative and functional evaluation is desirable in plant research. At the single-plant level, the number, size, and distribution of vascular bundles vary widely, posing a challenge to automatically and accurately identifying and quantifying them. In this study, a deep learning-integrated phenotyping pipeline was developed to robustly and accurately detect vascular bundles in Computed Tomography(CT) images...     

Silage fermentation characteristics of three common grassland species in response to advancing stage of maturity and additive application

This study investigated the effects of advancing stage of maturity and additive treatment on the fermentation characteristics of three common grassland species. Perennial ryegrass (PRG; Lolium perenne L., var. Gandalf), timothy (Phleum pratense L., var. Erecta) and red clover (Trifolium pratense L., var. Merviot) were harvested at three dates in the primary growth (11 May, 8 June and 6 July; Harvests 1–3) and ensiled with the following additive treatments: (1) control (i.e. no treatment), (2) formic acid‐based additive, (3) homofermentative lactic acid bacterial (LAB) inoculant and (4) heterofermentative LAB inoculant. Additive application to the PRG (irrespective of harvest date), the late‐harvest timothy (Harvest 3) and the red clover (Harvests 2 and 3) herbages had little impact on silage fermentation characteristics, where a lactic acid dominant fermentation already prevailed. However, the application of the formic acid‐based additive to the Harvest 1 and 2 timothy and Harvest 1 red clover herbages, where the silage fermentation characteristics were poorer, resulted in an increase in the proportion of lactic acid in total fermentation products and a decrease in pH. In contrast, the heterofermentative LAB inoculant had a negative impact on silage fermentation characteristics where a poor preservation prevailed in the corresponding control silage.     

马铃薯主要块茎性状杂种优势及配合力分析

对马铃薯9个亲本及其不完全双列杂交组配的18个杂种无性一代的8个性状进行了杂种优势和配合力分析。结果表明:①8个性状均具有一定程度的杂种优势,超中亲优势的大小顺序为:烂薯率>块茎产量>结薯数>淀粉含量>单个块茎重>薯形>块茎外观>结薯习性;超高亲优势的排列顺序则为:结薯数>单个块茎重>块茎产量>块茎外观>烂薯率>淀粉含量>薯形>结薯习性。②品种P(2L0031-17)、P(4陇薯3号)、P(7L0218-38)、P(995D-P-8)具有较好的一般配合力,是理想的亲本材料。③组合P1×P4、P2×P9在淀粉含量、块茎产量等性状上具有较高的特殊配合力,产生较强的杂种优势。在马铃薯高淀粉育种中应选择高淀粉材料作为亲本之一,选配组合时亲本最好采用高×高类型或高×低类型配置组合。     

Panicle-3D: A low-cost 3D-modeling method for rice panicles based on deep learning,shape from silhouette,and supervoxel clustering

Self-occlusions are common in rice canopy images and strongly influence the calculation accuracies of panicle traits. Such interference can be largely eliminated if panicles are phenotyped at the 3 D level.Research on 3 D panicle phenotyping has been limited. Given that existing 3 D modeling techniques do not focus on specified parts of a target object, an efficient method for panicle modeling of large numbers of rice plants is lacking. This paper presents an automatic and nondestructive method ...     

玉米Non-Reid群产量因素遗传改良效果及杂种优势和配合力分析

以No-Reid优良自交系PH4CV、PHB1M为基础材料,采用DH技术和常规技术方法,经过两轮改良,育成4个改良系,以4个改良系及PH4CV、PHB1M为父本,5个Reid优良自交系为母本,作5×6不完全双列杂交,设置3个密度梯度,研究单株产量的遗传增益、杂种优势及配合力。结果表明,第二轮改良系J1881,在3个密度下单株产量遗传增益高于原基础系和第一轮改良自交系;第一轮改良系J9D207、J1577遗传增益高于原始基础系。3种密度梯度下,4个改良系与Reid自交系单株产量杂种优势普遍存在,杂种优势最高的组合为J1590×J9D207、J1590×J1881。3个密度下,第二轮改良系J1881均有较高一般配合力,稳产性较好。     

13份玉米自交系品质性状及种子活力的配合力分析

采用NCII设计(6×7)组配42份杂交组合,采用随机区组试验,测定杂交组合的品质性状和种子活力指标,分析自交系性状配合力、遗传参数、相关系数。结果表明,组合活力指数的变异系数较大,其他性状均较小。品质性状一般配合力分析,5003改良系、Mo17变异株较优良。活力指标一般配合力分析,5003改良系、78599较优良,发芽率、发芽势、发芽指数、活力指数、脂肪、淀粉、蛋白质的广义遗传力和狭义遗传力均大于50%。除发芽率与发芽势、活力指数相关系数外,42份杂交组合的发芽率、发芽势、发芽指数、活力指数的相关系数均呈显著或极显著正相关。淀粉含量与活力指数、脂肪含量呈显著负相关;淀粉和蛋白质含量呈负相关,但未达到显著水平。     

5个78599玉米自交系与3个旅系间的配合力分析

用5个含78599种质资源的玉米自交系(P1)和3个旅系(P2)按不完全双列杂交(P1×P2)组成15个杂交组合,对玉米生育期、穗行数等7个农艺性状进行一般配合力和特殊配合力分析,以进一步了解这5个玉米自交系的特征特性.     

茶叶良种高效栽培技术与推广

本文阐述了茶叶良种先进高效栽培技术项目的完成情况,以及在研究和推广扦插繁殖技术、品种优化技术、老茶园嫁接换种、双条凹沟深栽、优化有机肥施用等技术中取得的先进经验。     

一种高效、准确测定油菜中维生素C含量的方法

为准确测定出油菜中维生素C的含量,在国标基础上,建立了一种高效、准确测定新鲜油菜维生素C含量的方法。结果表明：维生素C在测定范围内峰面积与标准液浓度线性关系良好,相关系数为0.9999。油菜维生素C含量测定的回收率为97.97%~101.40%,相对标准偏差RSD仅为1.84%,说明用该方法重现性良好,具有快速准确、稳定可靠等特点。贮藏温度越低,维生素C降解的速度越慢,用液氮贮藏样品更有利于维生素C的保存和精准鉴定;利用液氮冷冻并研磨样品更有利于样品中维生素C的提取,测得油菜中维生素C含量与仅均质化处理相比平均增加了约16%;液氮中贮藏的样品在不同时间下测定其维生素C含量并无显著变化,测得维生素C含量的RSD均小于2%。利用此方法可以测定较长时间保存样品中的维生素C,可满足高通量、高准确率的要求,有利于油菜的菜用营养和育种研究。     

15个化杀杂交小麦亲本配合力和杂种优势群的初步研究

为给小麦杂种优势利用提供依据,以15份普通小麦为材料,采用NCⅡ设计组配44个组合,研究了8个农艺性状的杂种优势和配合力。结果表明,杂种F₁的杂种优势是普遍存在的,各性状大都表现出正向优势;周麦22、西农889、西农375和罗大穗316的产量性状一般配合力相对效应较高,参与组配的强优势组合较多。在44个杂交组合中,（D177×罗大穗316）、（周麦22×花培878）、（周98165×西农375）、（周麦22×西农889）、（周麦22×200(1)穗2）、（周麦22×郑育麦9987）、（周麦22×07常261）、（周98165×西农889）、（周麦22×罗大穗316）、（周麦22×西农375）为强优势组合。利用普通小麦亲本8个性状的一般配合力将15份亲本划分为5类,直接以普通小麦亲本8个性状的表现值亦可将15份普通小麦划分为5类。     

茶叶鉴定专家系统的研究与开发

针对以往茶叶评定专家系统不足之处,用人工神经网络,建立一个功能完备的茶叶鉴定专家系统,并获得良好的分析结果,为茶叶理化分析的智能化研究奠定基础。     

双列杂交育种法配合力效应估计及其显著性检验的SAS实施

进行了应用SAS过程解决格里芬双列杂交育种方法2的配合力效应估计及其显性测验问题的研究。主要应用transpose过程、merge语句、统计代换gi=(1/(p 2))(hi-2zh／p)和sye=xye-(hi hj)/(p 2) 2zh/((p 1)(p 2))等，以及函数probt(t，df)、tinv(p，df)、lag()等，并以实例说明具体计算方法。     

21份玉米抗冷自交系配合力的分析及利用

本文以“八五”期间筛选的21份玉米抗冷自交系为被测系,采用NCⅡ交配设计的原理和方法,研究了12个性状的配合力及其群体遗传参数。结果表明：被测系各性状的一般配合力方差均达极显著水平。吉880等5个自交系的综合性状较优,可在育种中直接利用;而吉906等4个自交系的综合性状较差,需改良后方可利用;其余自交系部分性状的一般配合力较优,可用来改良其它自交系或作为选育二环系的基础材料。被测系多数性状的一般配合力方差大于特殊配合力方差,且多数性状的遗传力小于50%,环境方差偏大。     

Isolation and identification of a new tetrodotoxin-producing bacterial species, Raoultella terrigena, from Hong Kong marine puffer fish Takifugu niphobles

Puffer fish, Takifugu niphobles, collected from the Hong Kong coastal waters were screened for tetrodotoxin-producing bacteria. A Gram-negative, non-acid-fast, non-sporing and rod shaped bacterial strain (designated as gutB01) was isolated from the intestine of the puffer fish and was shown to produce tetrodotoxin (TTX). Based on the Microbial Identification (MIDI) and 16S-23S rDNA internal transcribed spacer (ITS) phylogenetic analysis, the strain was identified as Raoultella terrigena. The TTX production ability of the strain was confirmed by mouse bioassay, ELISA and mass spectrometry (MALDI-TOF). Our results reiterate that the TTX found in puffer fish was likely produced by the associated bacteria and TTX are widely produced amongst a diversity of bacterial species.