澳洲坚果果仁氨基酸含量的差异性分析

为了进一步了解澳洲坚果果仁的营养品质,为澳洲坚果良种选育提供参考依据,对5个品种澳洲坚果果仁氨基酸的种类、含量进行了测定与分析。结果表明:澳洲坚果果仁富含17种氨基酸,其中含有人体必需氨基酸7种,必需氨基酸占氨基酸总量的27.86%,并且比例稳定,变异系数仅为2.2%;澳洲坚果果仁氨基酸的种类以脂肪族氨基酸为主,芳香族和杂环族氨基酸也占有较大的比例。     

两个不同籽粒硬度小麦的比较蛋白组学分析

小麦是全球种植面积最大粮食作物,为全球45亿人提供日常蛋白和能量摄入的20%。弄清小麦籽粒硬度遗传基础,对于改良小麦品质具有重大意义。为探讨不同硬度小麦种子的分子基础,本实验选用西南麦区2个硬度差异极显著的小麦品种川麦66和蜀麦969,从蛋白水平上分析其种子蛋白差异表达情况,利用TMT定量蛋白质组学技术(tandem mass tags)结合生物信息学分析,分析差异表达的蛋白及其功能和通路等富集情况。结果表明,鉴定并定量了有效蛋白6020个,其中显著差异表达蛋白113个,在软质麦川麦66中上调表达的69个,下调表达的44个。差异蛋白GO富集分析共富集到65个GO条目,达到极显著富集水平的包括生物过程的1个条目、细胞组成的1个条目和分子功能的6个条目。推测营养库活性类蛋白、酶抑制剂活性类蛋白和谷胱甘肽代谢途径类蛋白可能参与小麦籽粒硬度形成。籽粒硬度相关蛋白可能主要分布于细胞胞外区,具有防御作用。从系统发育分析推测, puroindolines蛋白及其同源蛋白,可能既作为小麦籽粒贮藏蛋白,同时还能作为酶抑制剂调控籽粒发育。本研究为进一步探索小麦籽粒硬度遗传机制提供了参考。     

玉米籽粒突变体smk7的表型分析和基因定位

利用甲基磺酸乙酯(EMS)对玉米自交系B73进行诱变,获得一个可以稳定遗传的小籽粒突变体smk7(small kernel 7)。smk7成熟籽粒表现为体积变小,胚和胚乳发育缺陷,百粒重显著降低。突变籽粒发芽率仅为10%,且幼苗黄化不能生长成正常植株。成熟smk7胚乳中淀粉、蛋白、油分含量与野生型籽粒相比无显著差异,但突变体胚乳淀粉粒体积明显变小且形状不规则。smk7突变籽粒在授粉后12 d即可观察到明显的小籽粒和空瘪表型,石蜡切片显微观察显示突变籽粒的胚和胚乳发育迟缓,胚乳基部转移层细胞(BETL)相对于野生型细胞壁向内生长减少,发育受阻。用杂合植株(+/smk7)与多个自交系分别杂交,构建不同背景的F2分离群体,遗传分析结果表明该性状受单隐性核基因控制。利用靶向测序基因型分型(genotyping by target sequencing,GBTS)技术将基因初定位于2号染色体短臂,进一步精细定位发现该基因位于RM1433917和RM1535316两个标记之间约120 kb的物理范围内,共有8个蛋白编码基因。本研究为进一步克隆和解析SMK7基因调控玉米籽粒发育的分子机制奠定了基础。     

Effects of Calcium and Magnesium Hardness of Incubation Waters on the Hatching Success of Hybrid Eggs of ♀ Channel Catfish,Ictalurus punctatus × ♂ Blue Catfish,Ictalurus furcatus

Hatching efficiency is generally lower in channel catfish, Ictalurus punctatus × blue catfish, Ictalurus furcatus, hybrid catfish hatcheries compared to hatcheries hatching pond‐spawned channel catfish eggs. Egg quality and hatching water hardness are known variables influencing the efficiency of hybrid catfish fry production in hatcheries. Previous research recommended that at least 60 mg/L hardness had to be contributed only by calcium to optimize the hatching success of hybrid catfish eggs. However, whether the effect of waterborne magnesium in hatching waters facilitates or impedes the hatching success of hybrid catfish is not known. Two trials were conducted to determine the effects of calcium alone or magnesium hardness, in combination with the hatching success of hybrid catfish eggs. Trial 1 showed that if the previously identified minimum hardness criterion of 60 mg/L was met by calcium in the hatching waters, added magnesium had no effect on the hatching success of hybrid catfish eggs. Trial 2 showed that the previously identified minimum hardness of 60 mg/L can be met by either calcium alone or magnesium replacing up to 50% of the total hardness in the hatchery waters for optimal hatching success of hybrid catfish eggs. Calcium provides a specific requirement during embryonic development of catfish. The results from this study can be used to design treatment processes for hatchery water supplies to improve efficiency of hybrid catfish fry production in hatcheries.     

Mapping kernel texture in a soft durum (Triticum turgidum subsp. durum) wheat population

Kernel texture (”hardness”) is one of the major determinants of wheat quality and is primarily controlled by the Puroindoline (Pin) genes, located at the Hardness (Ha) locus. The absence of the Ha locus is responsible for the extremely hard kernels of durum wheat (T. turgidum subsp. durum). Recently, the Pin genes from a soft common wheat variety were introgressed into durum wheat through homoeologous recombination. The objective of this study was to map kernel hardness in a soft durum wheat population derived from the cross between the varieties “Creso” and “Langdon 1–678“. In all, 428 F₆ lines were evaluated for kernel hardness through the Single Kernel Characterization System; Hardness Index (HI) values ranged from −2 to 44. The same lines were genotyped using genotyping-by-sequencing, targeted amplicon sequencing, and sequence-tagged-site markers. A total of 8537 markers were used to conduct single marker-trait association analysis and two major significant regions were identified on chromosomes 3AL and 6AS each responsible for an additive effect of ∼6 HI units. Kompetitive allele specific markers targeting these regions were selected and tested in the whole population. To date, this is the first study to investigate the genetic factors behind hardness variation in durum wheat.     

锌肥对花生生理特性、产量及品质的影响

在大田试验条件下研究了锌肥对花生生理特性及产量品质的影响。结果表明,施用锌肥促进了花生的营养生长,增加了干物质积累量;提高了叶片叶绿素含量和净光合速率,增加了叶片过氧化物酶(POD)、超氧化物歧化酶(SOD)和过氧化氢酶(CAT)活性,降低了丙二醛(MDA)含量。施锌提高了花生产量,增加了籽仁脂肪和蛋白质的含量。其中施锌量为30kg/hm2时,花生产量最高,增产幅度达7.52%,其增产原因是增加了单株结果数,提高了果重。     

山西小麦品种籽粒硬度与主要品质性状研究

为明确山西省近十年育成小麦新品种的籽粒硬度和品质状况,利用单籽粒谷物特性测定仪(SKCS)、DA7200多功能近红外分析仪,对来自山西省近十年审定的56个小麦新品种的籽粒硬度、蛋白质含量、出粉率等指标进行了检测和分析。结果发现,山西省近十年审定的小麦品种中,硬质麦比例较高,为78%,混合型麦和软质麦比例较低,分别为12%和8%;硬度指数范围较宽,为16.33～78.93。经相关分析,小麦籽粒硬度指数与被测品质性状均呈正相关关系,其中,与出粉率、吸水率、最大拉伸阻力均呈极显著正相关(P0.01)。硬质麦的蛋白质含量、湿面筋含量、出粉率、沉降值等品质参数均显著高于混合型麦和软质麦。混合型麦的蛋白质含量、湿面筋含量、出粉率、沉降值等品质参数略高于软质麦。     

基于自适应带宽核密度估计的载荷外推方法研究

为了快速准确地得到玉米收获机车架的载荷谱,针对载荷谱编制过程中传统的载荷外推方法的局限性,提出一种基于四叉树算法的自适应带宽核密度估计(Kernel density estimation)算法,用来进行载荷外推.将经过预处理的实测原始载荷数据进行雨流计数统计,得到载荷循环均幅值矩阵,将小于载荷循环最大幅值10％的载荷滤...     

小麦籽粒形状参数分形特性研究及应用

小麦籽粒的长度、宽度、厚度、单粒质量等参数是小麦籽粒品质检测分级的重要参数。采用适合离散函数的网格法研究小麦籽粒的长度、宽度、厚度、单粒质量等参数间的分形特性。研究表明：对于研究的4种小麦籽粒,各参数间的分形维数在0～1之间,厚度与宽度间的分形维数差别较大,样品数为40和45粒时,利用厚度与宽度间的分形维数可将4种小麦籽粒完全分开。     

玉米籽粒收获机清选装置参数优化试验

针对玉米籽粒直收过程中清选作业损失率高、籽粒含杂率高的问题,开展玉米籽粒收获机清选作业参数优化试验,探究整机作业工况下清选装置作业参数对籽粒损失率和含杂率的影响规律,得到清选作业参数最优组合,并进行田间验证试验。玉米籽粒收获机清选作业参数较优水平区间为风机转速800～1 000 r/min,振动频率6～8 Hz,上清选筛筛孔开度15～25 mm。清选作业籽粒含杂率最优作业参数组合为风机转速1 000 r/min,振动频率7 Hz,上清选筛筛孔开度20 mm;籽粒损失率最优作业参数组合为风机转速900 r/min,振动频率6 Hz,上清选筛筛孔开度20 mm;清选作业综合指标最优作业参数组合为风机转速900 r/min,振动频率7 Hz,上清选筛筛孔开度20 mm。得到玉米籽粒收获机清选作业籽粒含杂率、籽粒损失率和综合指标的回归模型,田间验证试验表明,籽粒含杂率相对误差为5. 56%,籽粒损失率相对误差为5. 10%,综合指标相对误差为4. 60%,最优作业参数组合表现良好,且回归模型可靠。