Morphological and molecular characterization of Italian emmer wheat accessions

Summary The characterization of 39 Italian ecotypes and cultivars of Triticum turgidum L. spp. dicoccum Shrank ex Schübler (emmer wheat) was performed utilizing agro-morphological and molecular tools. Emmer wheat is a hulled species which grows wild in the Near East and is still cultivated in the Mediterranean Basin. Due to its characteristics, in Italy it is cultivated mainly in marginal lands of central and southern Italy, where local varieties, adapted to the natural environment where they originated, are used. Emmer wheat cultivation has been drastically reduced during the last century as a consequence of its low yield. Nevertheless, more recently, its agronomic and nutritive values, together with its use in health food products, made its cultivation economically viable in the marginal lands with a parallel increase of the cultivated area which is now more than 2000 ha. In the present paper the results of morphological evaluation, carried out in an experimental field in central Italy using a randomized block design with three replications, and molecular characterization are reported. The analysed material showed distinctive molecular traits and the existence of a huge amount of diversity not only between varieties, but also within them. When the accessions were clustered utilizing their genetic distance, the clusters were not always in agreement with the accessions origins. The obtained results gave information that can be useful for: (i) future registration of material, (ii) germplasm conservation and (iii) use of this valuable source of emmer germplasm for future breeding programmes.     

Morphological and molecular characterization of melon accessions resistant to Fusarium wilts

Fusarium wilt incited by Fusarium oxysporum f. sp. melonis (F.o.m) is one of the most widespread and devastating melon diseases. While resistance to physiological races 0, 1, and 2 is relatively frequent in different botanical varieties, sources of resistance to race 1,2 are restricted to a few Far-Eastern accessions. In this work, the results of a screening for resistance to F.o.m. race 1,2 among 32 accessions are presented. Three Japanese accessions (‘Kogane Nashi Makuwa’, ‘C-211’, and ‘C-40’) showed the highest resistance levels, but useful levels of resistance were also detected in one Russian ‘C-160’ and two Spanish (‘C-300’ and ‘Mollerusa-7’) accessions. These resistant materials, together with other accessions previously described as resistant to F.o.m. races 0, 1, and/or 2 have been morphologically and molecularly characterized. Based on cluster analysis, these accessions have been grouped according to the botanical subspecies they belong to. Assessment of genetic diversity indicated that the resistant accessions to races 0, 1 and 2, are scattered along the established clusters. On the other hand, high levels of resistance to the race 1,2 could be found only among accessions belonging to Cucumis melo subsp. agrestis, nevertheless, a certain degree of resistance to this race could also be found within some accessions belonging to subsp. melo. As far as we know, this is the first report of resistance to F.o.m race 1,2 found out from the Far-Eastern melon material. Based on fruits characteristics, it appears that several inodurus and cantalupensis accessions could be exploited in breeding programs as resistance sources to F.o.m races 0, 1 and/or 2 for the improvement of these melon types. The accessions with the highest levels of resistance to the race 1,2 appeared to be very distant both molecularly and morphologically from the commercial types. Nevertheless ‘C-160’, ‘C-300’, and ‘Mollerusa-7’ classified as var. inodorus are morphologically very similar to the Spanish commercial types and might be used as resistant sources in breeding these melon types.     

Actions for ex situ conservation of Gloriosa superba L. - an endangered ornamental cum medicinal plant

Factors affecting in vitro propagation and microtuberization were evaluated for Gloriosa superba L., an endangered ornamental cum medicinal plant having limited reproductive capacity. Surface sterilization of tuber explants with 0.1% mercuric chloride (HgCl₂) for 5 min eliminated the contamination effectively with highest survival rate. Among the various combinations used, Murashige and Skoog (MS) medium with 2.0 mg L^?1 6-benzylaminopurine (BAP) + 0.5 mg L^?1 α-naphthalene acetic acid (NAA) containing 3% sucrose with 16-h photoperiod exhibited the greatest in vitro tuberization (3.2) with the highest shoot regeneration frequency (90%). The longest tuber regeneration occurred on MS media containing 4% sucrose. Transfer of in vitro-regenerated shoots to half-strength MS medium with 1.0 mg L^?1 indole-3-butyric acid (IBA) + 0.5 mg L^?1 NAA showed maximum root induction (66.6%). The in vitro-grown plantlets were successfully acclimatized and transplanted to sterilized soil and sand mixture (3:1) in the glasshouse with 70% survival. The colchicine content was determined in the tubers of ex vitro plants by HPLC using the same retention time (1.5 min) as that of the standard colchicine. This revealed that the micropropagation protocol developed by us for rapid mass production could be used as raw material for colchicine extraction and provides a basis for germplasm conservation and genetic improvement of G. superba.     

Morphological characterization of kale populations from northwestern Spain

Crops belonging to the genus Brassicaare widely grown in Galicia (northwesternSpain). Kales (Brassica oleracea L.convar. acephala (DC.) Alef.) are oneof the most important Brassica cropsin this region where landraces aretraditionally grown by farmers on smallplots for either human or animal food.Fifteen kale populations from northwesternSpain were evaluated in two locations andtwo planting dates (early and late). Theobjectives were i) to study theirmorphological diversity, ii) to determinetheir relationships, and iii) to evaluatetheir morphological and agronomiccharacteristics that could be incorporatedto breeding programs in the future.Significant differences were found amongpopulations for all traits while genotype ×environment interaction was not significantfor most of them. Cluster and principalcomponent analysis were performed todetermine relationships among landraces andto obtain information on the usefulness ofthe characters for the definition ofgroups. The phenogram showed five groups,two groups including most of thepopulations and three small independentgroups. Groups of landraces were associatedwith the geographical origin and withmorphological differences amongpopulations, mainly with the length oftheir vegetative phase: north and earlypopulations (cluster A) and south and latepopulations (cluster B). Morphologicaldiversity was higher in coastal populationsthan in inland populations. As conclusion,the populations evaluated in this workdisplay a wide diversity of traits whichenable us to select and combine someinteresting landraces for important traitsin order to obtain improved varieties.     

Morphological and molecular characterization of the second backcross progenies of Ogu-CMS Chinese kale and rapeseed

Ogura cytoplasmic male sterility (Ogu-CMS) is widely used in the production of commercial hybrids of Brassica oleracea. However, the widespread application of the Ogu-CMS system in B. oleracea has hindered the germplasm innovation of Ogu-CMS resources due to the lack of a natural restorer line. Previously, the Ogu-CMS fertility-restored interspecific hybrids between rapeseed 15Y403 (2n = 38, AACC) and Chinese kale JL1 (2n = 18, CC) have been successfully produced. However, these progenies, which still contained a large proportion of rapeseed genomic components, showed poor fertility and a low seed setting rate under natural pollination. To improve fertility and seed setting, a successive backcross with JL1 was performed to produce BC₂ progenies. Screening with the Rfo-specific marker, five individuals harboring the Rfo gene were identified among 98 BC₂ progenies. These five individuals underwent background marker screening and an evaluation of agronomic traits and fertility. One individual (code: 15Q23) was identified with higher pollen viability, better seed setting under natural pollination, and a closer genetic background to the parent Chinese kale JL1. Many morphological traits showed no significant differences (P < 0.05) between 15Q23 and the backcross parent JL1. However, the average seed setting of 15Q23 under natural pollination was 0.72 seeds per pod, which was 50 times higher than that of BC₁ progenies, and the average pollen viability was 87.07%, which was significantly better than that of the F₁ and BC₁ plants (P < 0.01). The genetic background of 15Q23 was more closer to the parent JL1 than that of BC₁ plants and another BC₂ fertility-restored individual, with 82% of the polymorphic alleles being the same as those of the parent Chinese kale JL1. Thus, the individual 15Q23 could be used as a donor plant for further backcrosses. This study lays the foundation for the development of Ogu-CMS restorer material in B. oleracea.     

Antimicrobial and micro Raman spectroscopy of selected Zingiberaceae species from Northeast India

Antimicrobial activity of crude rhizome oils from some important members of Zingiberaceae from Northeast India was carried out in the present study. The plants used were Curcuma amada, C. longa, Zingiber moran, and Z. zerumbet. Rhizomes of the four species were collected and rhizome oil was extracted using six different polar and non-polar solvents. The antimicrobial property of the crude oil was studied against human pathogens using disc-diffusion and viability assay. The rhizome oil of all the 24 extracts exhibited potent antimicrobial activity against all pathogenic bacterial and fungal strains tested. Hydrodistilled fractions of the four species studied showed better effect among all solvents. Water extract of Z. moran was found to be the highest effective antimicrobial agent of all. Antibacterial effect of the water fractions was also characterized against Gram-positive and Gram-negative bacteria using micro Raman spectroscopy. This investigation shows that the essential oils from the wild and domestic species of the family Zingiberaceae from Northeast India are a potential source of bioactive compounds with tremendous medicinal, economic, and therapeutic value. The wild and endemic species Z. moran represents an interesting and promising source of plant-derived antimicrobial agent in the development of new drugs against pathogens.     

彩叶草叶片cDNA文库的构建与分析

用植物(叶)总RNA抽提试剂盒提取彩叶草红色品种顶部叶片总RNA,用SMART cDNA Library Construction Kit构建cDNA文库。经测定原始文库滴度为1.2×106 pfu/ml,扩增总文库滴度为6.7×109 pfu/ml,重组率达到98%,插入片段在0.5 kb到2 kb之间,1 kb以上的占60%。通过PCR检测,从总文库中检测到了彩叶草CHS、DFR 及ANS基因的特异片段。各项指标都表明,已获得较高质量的cDNA文库,为彩叶草叶色基因的分离克隆,彩叶草类黄酮类色素合成的分子调控的研究奠定了基础。     

Characteristics of long-distance mobile mRNAs from shoot to root in grafted plant species

Thousands of long-distance mobile mRNAs were identified from different grafting systems, based on high-throughput sequencing technology. Moreover, the long-distance delivery of RNAs was proved to involve multiple mechanisms. Here, we analyzed the homology, motif, and tRNA-like structure(TLS) of long-distance mobile mRNAs identified by RNA-seq as well as the RNA-binding protein(RBP) in nine grafting combinations including Arabidopsis thaliana, Vitis vinifera, Cucumis sativus, Citrullus lanatus, N...     

领春木幼苗形态及生物量分配对光环境的响应

研究了旷地、林窗和林下三种不同生境中,领春木(Euptelea pleiospermum Hook.f.et Thoms.)幼苗的生长、形态特性、生物量及其分配对不同光环境的响应。结果表明,1）光资源不足的情况下,领春木幼苗生长受到抑制;2）生长于林窗的领春木幼苗有更多纵向生长趋势以获取更多的光资源,并通过增加叶片数和总叶面积来提高对光能的利用;3)领春木幼苗通过提高根生物量比和降低比叶面积,减小强光对幼苗的损伤;光强较弱时,则是将更多的生物量投资于地上部分,主要用于高生长和叶生长,以增加对光辐射的吸收。领春木生长环境光照偏弱,但其幼苗适于生长于光照偏强的环境,这可能是领春木幼苗在其种群更新中受到光环境抑制的原因,加上对成年植株及其生长环境人为的破坏,可能是导致领春木数量减少的原因之一。     

半夏属药用植物trnL - F序列与种间遗传关系分析

为了给半夏属物种鉴别和种间遗传关系分析提供分子佐证,对中国半夏属植物5个种共9份材料的trnL-F进行克隆测序,用ClustalX1.81,PAUP4.0软件进行序列分析,采用邻接法(Neighbor-Joining,N-J)构建系统发育树。结果表明所测物种的序列全长1027～1136bp,G+C含量34.6%～36.8%,经排序并两端切平后,序列长994bp,当空位始终做缺失处理时,产物有29个变异位点,6个信息位点。聚类结果显示,半夏属物种总体聚为2大分支,虎掌为1个分支,另外8份材料:滴水珠、盾叶半夏、石蜘蛛以及半夏聚为1个分支。采用邻接法得到的9份半夏属药用植物的分子系统树有一定的差异,表明这9份半夏属药用植物的物种分化不完全,序列进化不一致,是物种鉴别的有效分子标记。     

Morphological and molecular diversity of Nordic oat through one hundred years of breeding

Summary Genetic diversity in microsatellites and development of agronomical characters in Nordic oat cultivars (Avena sativa) from the 20th century, ranging from landraces to new cultivars, were studied. A clear development in agronomical characters has taken place in this period: Straw length has been reduced, harvest index has increased and heading date has declined. The persistent oat breeding effort in the northern part of the region was indicated by the data, since cultivars from this region showed higher harvest index. Also adaptation to shorter summers was apparent in cultivars from the most northern part of the area. When comparing cultivars released after 1940 to the landraces, the loss of diversity revealed for the agronomical characters was also indicated by the molecular data. This indicates that a more general loss of diversity has taken place in the period, possibly due to random factors during the breeding process (bottleneck effect). The reduction in diversity revealed by recent cultivars at an agronomical as well as a molecular level emphasises the importance of implementing a conservation strategy for older material in order to secure genetic diversity for future oat breeding efforts.     

Morphological and molecular analysis of androgenetic, selfed and backcrossed plants produced from a Hordeum vulgare x H, bulbosum hybrid

Anther culture (AC) was carried out on a fertile triploid hybrid between Hordeum vulgare L. (cultivated barley) and H. bulbosum L, (bulbous barley grass) to determine whether AC-derived regenerants differed from progeny obtained through selfing and backcrossing. Chromosome counts were carried out on all plants and DNA was extracted from them to prepare Southern blots for molecular analysis. To identify true recombinants, the blots were probed with rye repetitive sequence probes (pSc119.1 and pScl19.2). which hybridize strongly and specifically to H. bulbosum DNA. Twenty probes that detect single- or low-copy sequences were hybridized with Southern blots containing restricted DNA extracted from 25 AC-derived plants, 11 selfed and six backcrossed progeny that showed hybridizations with pScll9. Although restriction fragment length polymorphisms (RFLPs) were only observed using probes that map to four of the possible 14 chromosome arms, an introgression associated with chromosome 6HS was frequently observed among plants derived from AC. selfing and backcrossing. Plants from AC differed from selfed and backcrossed progeny in their chromosome number; unique RFLP bands that were occasionally observed may indicate chromosomal rearrangements.     

基因差异表达与作物杂种优势分子机理研究

本文在回顾杂种优势机理研究历史的基础上,介绍了用基因差异表达技术来研究作物杂种优势分子机理的原理,以及在作物杂种优势分子机理研究上的进展,并对作物杂种优势分子机理研究的前景进行预测和展望.     

分子标记技术及其在作物育种中的应用

论文综述了分子标记的基本类型及其在作物遗传育种中的应用,分析了应用过程中存在的问题,提出了解决的方法,并讨论了其应用前景。     

Quantitative and molecular characterization of heat tolerance in hexaploid wheat

Understanding the genetic basis of tolerance to high temperature is important for improving the productivity of wheat (Triticum aestivum L.) in regions where the stress occurs. The objective of this study was to estimate inheritance of heat tolerance and the minimum number of genes for the trait in bread wheat by combining quantitative genetic estimates and molecular marker analyses. Two cultivars, Ventnor (heat-tolerant) and Karl92 (heat-susceptible), were crossed to produce F₁, F₂, and F₃populations, and their grain-filling duration (GFD) at 30/25 ^°C 16/8 h day/night was determined as a measure of heat tolerance. Distribution of GFD in the F₁ and F₂ populations followed the normal model (χ², p > 0.10). A minimum of 1.4 genes with both additive and dominance effects, broad-sense heritability of 80%, and realized heritability of 96%for GFD were determined from F₂ and F₃ populations. Products from 59primer pairs among 232 simple sequence repeat (SSR) pairs were polymorphic between the parents. Two markers, Xgwm11 andXgwm293, were linked to GFD by quantitative trait loci (QTL) analysis of the F₂ population. The Xgwm11-linked QTL had only additive gene action and contributed 11% to the total phenotypic variation in GFD in the F₂population, whereas the Xgwm293-linked QTL had both additive and dominance action and contributed 12% to the total variation in GFD. The results demonstrated that heat tolerance of common wheat is controlled by multiple genes and suggested that marker-assisted selection with microsatellite primers might be useful for developing improved cultivars. This revised version was published online in August 2006 with corrections to the Cover Date.     

EMS诱变刺荞的形态突变体鉴定与分析

为构建苦荞EMS突变体库和为苦荞功能基因组学研究准备基础材料,利用化学诱变剂甲基磺酸乙酯（ethyl methane sulfonate,EMS）诱变处理刺荞种子,对获得的M₂代材料进行生物学性状与农艺性状鉴定,并对部分M₂代材料播种家系进行验证。对M₂代全生育期田间表型进行观察鉴定,共获得480份突变体材料,包括子粒、叶片、茎秆及生育期等生物学特性与主要农艺性状突变体,变异类型丰富,尤其是首次发现了子粒多棱苦荞新材料,并发现了自然突变中少见的变异类型,如子粒开裂等变异类型。所构建的刺荞EMS突变群体较理想,可望有效用于苦荞功能基因组研究和苦荞遗传改良。