Variation of the amino acid scores and of the nitrogen-to-protein conversion factors in barley grain as a function of nitrogen content as compared with wheat and rye

Barley grains (9 samples from 7 cultivars) with nitrogen contents (N) ranging from 1.45 to 4.01% of dry matter were analysed for their amino acid (AA) composition with high accuracy from six different hydrolysates per sample. AA levels in grain increased as linear functions ofN with correlation coefficients close to unity. A comparison with literature data confirmed that the AA composition of any grain sample of normal barley can be predicted from itsN for all phenotypes and genotypes. AAs in grain protein changed as hyperbolic functions ofN which increased for Phe, Pro and Glx but more or less strongly decreased for the other AAs. By plotting AA scores againstN, barley proteins were shown to be always richer than wheat and rye in Val and Phe + Tyr; sometimes richer than both other species forN<2 (Lys); 2.2 (Leu and Ile); 3.4 (Thr); sometimes intermediate to wheat and rye above the latterN values. They were also intermediate in sulphur AAs forN<1.9 and drastically poorer forN>1.9. However, they were richer than both other species in Trp forN>1.6. The hyperbolic variations of non-protein nitrogen and nitrogen-to-protein conversion factors were determined as a function ofN and also compared with those of wheat and rye.     

毛细管电泳技术及其在作物贮藏蛋白研究中的应用

毛细管电泳 (Capillary Electrophoresis,CE)是近年发展起来的一种新的分离技术 ,已在蛋白质、氨基酸、核酸等的分离分析方面显示出极大的优越性。目前 ,国内外都开展了毛细管电泳技术用于作物贮藏蛋白分离分析的研究 ,并取得了很大的进展。本文介绍了毛细管电泳技术的发展概况、分离原理及其主要模式 ,总结了目前国内外在小麦、大麦、燕麦等麦类作物贮藏蛋白毛细管电泳分离中的研究进展 ,并展望了其应用前景。     

小麦族物种线粒体基因rrn18-trnfM区域的序列多样性分析

为了研究线粒体基因组在小麦族物种中的遗传变异与进化关系，选用小麦族的14个二倍体及7个多倍体物种，对其线粒体rrn18-trnfM基因区域进行PCR扩增并对扩增所得的片段进行克隆测序。获得大小不同的2种片段类型，大片段为513或515bp，小片段为447或449bp。其主要差异在trnfM区，即大片段存在trnfM基因，小片段缺失trnfM基因，再次证明以前报道的大麦属和小麦属间的分歧。而中间偃麦草同时存在两扩增片段类型，表明多倍体物种mtDNA具有双亲遗传现象。中间偃麦草的RT-PCR分析发现小片段没有转录，大片段能转录，因而考虑高频重组和选择性表达作为中间偃麦草的线粒体基因组独特的进化系统，这与核基因组进化系统不同。     

麦类作物不同品种混合群体的生产性能评述

同种作物不同品种混作由于表现出比单作在产量及其稳定性、抗病性、品质等方面的优势而受到广泛关注,在国内外已做了大量研究,其中尤以对麦类作物研究较多。回顾了麦类作物不同品种混作的研究成果,评述了麦类作物不同品种混合群体的生产性能,并对产生各种效应的机理进行了总结,最后对麦类作物混作的应用和需要进一步研究的问题提出了建议。     

Triticeae plants preferentially responded to S-1-α-methylbenzyl-3-p-tolylurea in root growth and tetrazolium reduction assays

Optically active 1-α-methylbenzyl-3- p -tolylurea (MBTU) shows diverse plant physiological properties. Gramineae plants exhibit enantioselective root growth inhibition by R / S -MBTU. In the present paper, the dose–growth response (DGR) towards the optically active MBTUs was examined in the tribe Triticeae plants, including Hordeum vulgare L., Secale cereale L., Triticum aestivum L. and Aegilops cylindrica Host., and compared with those of the genus Bromus ( B. inermis Leyss), which is classified into the tribe Bromeae, and the genus Oryza . In spite of their phylogenetic difference, the Triticeae plants responded homogeneously in their chiral recognition. Of particular interest, is the result of the dichotomic enantioselective response of tested Gramineae plants. Only the genus Oryza responds to R -MBTU, and the tribes Triticeae ( Triticum , Aegilops , Secale and Hordeum ) and Bromeae ( Bromus ) preferentially respond to the S -enantiomer. The tetrazolium–phenazine methosulfate–formazan (TPF) assay was demonstrated to measure redox activity of root tips of the MBTU-treated Oryza sativa and T. aestivum , which are the typical dichotomic, enantioselective-responsive plants. In Oryza and Triticum root tips, enantioselective responses of reduction activity in TPF assays were strongly related to those of root growth inhibition in DGR assays, suggesting aggressive participation of the MBTU in the generation of the reducing mechanism in mitochondria.     

Cytogenetic analysis of Kengyilia mutica (Keng) J. L. Yang, Yen and Baum (Poaceae: Triticeae)

Kengyilia mutica (Keng) Yang, Yen et Baum is a hexaploid perennial grass of the tribe Triticeae native to western central China. The analyzer species with known genomic constitution used to produce interspecific hybrids with the target taxon were Roegneria kamoji Ohwi (StStHHYY), K. hirsuta (Keng) J. L. Yang, Yen et Baum (PPStStYY) and K. rigidula (Keng) J. L. Yang, Yen et Baum (PPStStYY). Analysis of metaphase I pairing configurations in the F₁ hybrids indicates that K. mutica possesses the P, St and Y genomes, with only minor structural rearrangements. Chromosome pairing in hybrids supports the inclusion of K. mutica in the genus Kengyilia.     

猬草属及其近缘属种子胚乳细胞多样性研究

对小麦族猬草属、赖草属、新麦草属、拟鹅观草属、披碱草属和Lophopyrum共6属20份材料的胚乳细胞特征进行解剖观察,发现不同属种植物种子胚乳细胞存在丰富的多样性,不同物种的胚乳细胞在大小、形状和数量上均表现出差异,但不能很好地反映种以上的组、属以及基因组间的差异。     

小麦族物种线粒体基因rrn18–trnfM区域的序列多样性分析

为了研究线粒体基因组在小麦族物种中的遗传变异与进化关系,选用小麦族的14个二倍体及7个多倍体物种,对其线粒体rrn18-trnfM 基因区域进行PCR扩增并对扩增所得的片段进行克隆测序。获得大小不同的2种片段类型,大片段为513或515 bp,小片段为447或449 bp。其主要差异在trnfM区,即大片段存在trnfM基因,小片段缺失trnfM基因,再次证明以前报道的大麦属和小麦属间的分歧。而中间偃麦草同时存在两扩增片段类型,表明多倍体物种mtDNA具有双亲遗传现象。中间偃麦草的RT-PCR分析发现小片段没有转录,大片段能转录,因而考虑高频重组和选择性表达作为中间偃麦草的线粒体基因组独特的进化系统,这与核基因组进化系统不同。     

麦类作物化感作用及其分子生态学研究

本文综述了近年来国际上研究麦类作物化感作用的新进展,着重介绍了小麦和大麦的化感作用种质资源的筛选与评价。在此基础上运用现代分子生物标记技术ISSR,分析了麦类化感作用的遗传多样性,并进一步阐明了小麦和大麦化感物质的研究现状。最后根据当前植物化感作用研究的发展趋势,提出化感作用基因表达与信号调控的分子生态学及根际生物学过程是未来麦类作物化感作用的重点领域。     

小麦族猬草属和赖草属物种的叶表皮微形态研究

对4种猬草属和12种赖草属植物叶表皮进行光镜观察,发现叶下表皮呈现较丰富的微形态差异,主要表现在长细胞形态、短细胞类型及分布、刺毛的有无、气孔器的形态与分布等;表皮微形态的性状组合特征与植物所生长的生态环境有较大的关联;叶表皮微形态具有区分物种的价值,但在属间或属内分组水平上的分类意义不大。