桂花品种资源的遗传多样性分析

根据桂花（Osmanthus fragrans）品种的形态特征,结合AFLP分子标记,对部分桂花栽培品种进行了遗传多样性分析。结果表明,桂花品种之间存在着较为丰富的遗传多样性,AFLP分子标记检测到的多态性条带占总扩增条带的57.46%。根据桂花品种的主要性状特征,利用数值分类法对其进行分类,并用UPGMA法对AFLP结果进行聚类分析,结果均显示桂林地区的桂花品种存在明显的区域性,花色可以作为重要的分类标准,同时对桂花品种的分类系统进行了探讨。     

桂花品种资源的遗传多样性分析

根据桂花(Osmanthus fragrans)品种的形态特征, 结合AFLP分子标记, 对部分桂花栽培品种进行了遗传多样性分析。结果表明, 桂花品种之间存在着较为丰富的遗传多样性, AFLP分子标记检测到的多态性条带占总扩增条带的57.46%。 根据桂花品种的主要性状特征, 利用数值分类法对其进行分类, 并用UPGMA法对AFLP结果进行聚类分析, 结果均显示桂林地区的桂花品种存在明显的区域性, 花色可以作为重要的分类标准, 同时对桂花品种的分类系统进行了探讨。     

RAPD技术与桂花品种分类和鉴定

简介了随机扩增多态ＤＮＡ（ＲＡＰＤ）技术的原理,及对桂花品种分类鉴定的必要性,并建议开展ＲＡＰＤ技术在桂花品种分类鉴定的应用研究。     

桂花品种分类及木犀属种质资源的利用

在总结桂花栽培品种分类的基础上,根据桂花的开花季节、花色、花期、子房发育状况（能否结实）及营养器官等性状,既考虑品种进化关系和传统分类方法,又密切结合生产实际的需要,提出了桂花品种分类的五级标准。并对木犀属的地理分布和种质资源的利用进行了讨论。     

不同品种桂花转录组分析及桂花精油成分差异的初步探讨

为丰富桂花转录组数据信息,阐明不同品种桂花精油合成的分子差异,本研究选择三种不同品种桂花,通过Illumina Hiseq2000平台测序,总计产出14.4G数据,三个品种的桂花样品共获得70029个Unigene序列,平均长度762 nt,N50达到1183 nt。通过Unigene的表达差异分析与通路富集分析,发现与桂花精油物质合成途径有关的差异基因主要注释在二萜合成、萜类骨干化合物合成、单萜合成、倍半萜与三萜合成、苯丙烷类合成、苯丙酸类代谢、亚麻酸代谢以及亚油酸代谢8个通路中。而三种桂花差异基因均显著富集的通路则注释在苯丙烷类合成、苯丙酸类代谢、二萜合成以及萜类骨干化合物合成通路,共获得650个编码精油物质合成途径中54个差异酶的差异基因。本研究建立了以金球桂、白洁和日香桂为代表的桂花转录组数据库。通过转录组分析,确定了不同品种桂花精油物质合成差异的表达途径,初步分析了转录组数据库中与精油物质合成途径相关的差异基因。本研究将为桂花精油成分代谢调控及体外表达提供依据。     

利用RAPD研究桂林桂花品种间的亲缘关系

采用随机扩增多态性DNA(RAPD)技术,从100个随机引物中筛选出扩增效果较好的20个引物,分 析桂林市23个桂花品种的基因组多态性。20个随机引物共检测到193个位点,其中多态位点114个,占 59.1%。并进行了聚类分析,构建出树状聚类图,将这些品种划分为4个品种群,与传统分类学结果一致。结 果表明,以基因型而不是以表现型为基础,分析桂花品种间的区别是可能的。该技术为解决桂林市的桂花品 种分类问题提供了重要依据。     

桂花非挥发性成分及药理活性研究进展

桂花在我国具有悠久的栽培与研究历史,目前的研究多集中于食用、精油和浸膏等方面。为了阐明桂花的综合利用价值,本文对桂花中的非挥发性成分的提取、分离、鉴定及其药学活性研究进行了综述。桂花的非挥发性成分包括黄酮类、萜类、木脂素类和苯丙素类等。桂花提取物具有抗炎、抗菌、抗氧化、抑制黑色素合成、细胞毒、抗衰老等药理学活性。通过对桂花提取方法和活性成分的研究,为其深度开发和高效综合利用提供参考。     

桂花SRAP—PCR体系的确立及验证

以桂花[Osmanthus fragrans (Thunb. ) Lour. ]品种'早银桂'的总DNA为模板,对SRAP-PCR扩增体系中的模板DNA用量,Mg2+、 dNTPs和引物浓度以及Taq DNA聚合酶用量进行单因子实验, 确立了适合桂花总DNA的 SRAP-PCR反应体系:反应体系总体积10 μL,包括30 ng模板DNA、 2.5 mmol·L-1 Mg2+ 、 0.20 mmol·L-1dNTPs、 0.4 μmol·L-1上下游引物和0.75 U Taq DNA聚合酶及1×PCR buffer.采用SRAP引物组合pm21-em8,以78个桂花品种的总DNA为样品,对优化的SRAP-PCR反应体系进行初步验证,共扩增出632条带,多态性条带百分率75.32%;扩增位点15个,多态性位点百分率为86.67%.运用优化的SRAP-PCR体系,使用筛选出的18对SRAP引物组合对88个桂花品种、1个桂花野生种以及2个外类群[柊树O. heterophyllus (G. Don) P. S. Green和华东木犀O. cooperi Hemsl. ]的总DNA进行扩增,共扩增出296个位点,其中多态性位点248个,多态性位点百分率为83.78%.实验结果显示,运用优化的SRAP-PCR反应体系获得的DNA条带清晰、扩增结果稳定、多态性较丰富;SRAP分子标记可用于桂花遗传多样性、品种资源鉴定、亲缘关系以及系统进化等方面的研究.     

响应面优化回流提取桂花不同品种种子油工艺及脂肪酸组成分析

为优选桂花不同品种种子油的提取工艺及分析其脂肪酸组成,本文运用响应面法对桂花种子油的回流提取工艺进行优化,并利用GC-MS法测定桂花种子油的脂肪酸组成,同时还考察了桂花种子油的体外抗氧化活性。结果表明,桂花四大品种种子油的最佳提取工艺分别为金桂:回流时间72. 0 min、温度80. 0℃、料液比1∶13mL/g;银桂:回流时间120 min、温度80. 0℃、料液比1∶12 mL/g;丹桂:回流时间60. 0 min、温度70. 0℃、料液比1∶13 mL/g;四季桂:回流时间71. 0 min、温度71. 0℃、料液比1∶13 mL/g。在上述条件下,桂花四大品种种子油的提取率分别为15. 0%、17. 8%、18. 0%和16. 0%。进一步的GC-MS检测发现丹桂和银桂种子油中不饱和脂肪酸可达96. 0%以上,且主要以油酸和亚油酸为主。体外抗氧化活性结果显示,当质量浓度为5μg/mL时,桂花种子油对DPPH的清除率均大于79. 0%。上述研究结果为桂花种子这种农业废弃资源的再利用和开发提供了参考。     

桂花开花进程中花瓣色素、可溶性糖和蛋白质含量的变化

以软叶丹桂(O smanthus fragrans‘Ruanye Dangu i’)、柳叶银桂(O.fragrans‘Liuye Y ingu i’)和四季桂(O.fra-grans‘Sijigu i’)3个桂花品种为试材,研究了桂花不同品种开花和衰老过程中的花瓣色素、可溶性糖和蛋白质等的变化。结果表明:(1)从初花期到盛花期再到衰老期,类胡萝卜素和花青素的含量先升高再下降,与花瓣颜色深浅变化一致,表明不同时期花色的变化主要由色素的含量变化所引起。(2)3个桂花品种花瓣的含水量、可溶性糖和可溶性蛋白质的含量均呈下降趋势,而花期较长的软叶丹桂比柳叶银桂和四季桂降幅要低,而柳叶银桂和四季桂之间差异不显著。     

A new strategy employed for identification of sweet orange cultivars with RAPD markers

We optimized RAPD techniques by increasing the length of RAPD primers and performing a strict screening of PCR annealing temperature to distinguish 60 sweet orange cultivars from the Research Institute of Pomology at the Chinese Academy of Agricultural Sciences. A new approach called cultivar identification diagram (CID) was used to improve the efficiency of RAPD markers for cultivar identification. Thirteen effective primers were first screened from 54 RAPD arbitrary 11-mer primers based on their amplification products and amplified polymorphic bands; they were then used for PCR amplification of all 60 cultivars. All cultivars were manually and completely separated by the polymorphic bands appearing in DNA fingerprints from 13 primers; a CID of the 60 sweet orange cultivars was then constructed. This CID separated all the cultivars from each other, based on the polymorphic bands; the corresponding primers were marked in the correct positions on the sweet orange CID. The CID strategy facilitates the identification of fruit cultivars with DNA markers. This CID of sweet orange cultivars will be very useful for the protection of cultivar rights and for early identification of seedlings in the nursery industry.     

Molecular phylogenetic reconstruction of Osmanthus Lour. (Oleaceae) and related genera based on three chloroplast intergenic spacers

Although polyphyly of Osmanthus has been suggested by different authors, the conclusions of previous studies have lacked robust support due to limited sampling or a paucity of phylogenetic characters. In this study, the phylogeny of Osmanthus was explored using sequences of three informative chloroplast regions (psbJ-petA, rpl32-trnL and rps16-trnQ), including all the five sections of the genus and eight closely related genera. The results confirm that Osmanthus, as presently circumscribed, is a polyphyletic group, containing three or four distinct lineages, i.e. sect. Leiolea (lineage I), sect. Notosmanthus (lineage III), sects. Osmanthus (excluding O. decorus), Siphosmanthus and Linocieroides (lineage IV), and an uncertain lineage including only O. decorus (lineage II). These results emphasize that the generic delimitation within subtribe Oleinae is in need of revision. In addition, this study found that the four cultivar groups of sweet osmanthus formed a paraphyletic clade, implying that cultivated sweet osmanthus might originate from several species.     

Prunasin hydrolases during fruit development in sweet and bitter almonds

Amygdalin is a cyanogenic diglucoside and constitutes the bitter component in bitter almond (Prunus dulcis). Amygdalin concentration increases in the course of fruit formation. The monoglucoside prunasin is the precursor of amygdalin. Prunasin may be degraded to hydrogen cyanide, glucose, and benzaldehyde by the action of the β-glucosidase prunasin hydrolase (PH) and mandelonitirile lyase or be glucosylated to form amygdalin. The tissue and cellular localization of PHs was determined during fruit development in two sweet and two bitter almond cultivars using a specific antibody toward PHs. Confocal studies on sections of tegument, nucellus, endosperm, and embryo showed that the localization of the PH proteins is dependent on the stage of fruit development, shifting between apoplast and symplast in opposite patterns in sweet and bitter cultivars. Two different PH genes, Ph691 and Ph692, have been identified in a sweet and a bitter almond cultivar. Both cDNAs are 86% identical on the nucleotide level, and their encoded proteins are 79% identical to each other. In addition, Ph691 and Ph692 display 92% and 86% nucleotide identity to Ph1 from black cherry (Prunus serotina). Both proteins were predicted to contain an amino-terminal signal peptide, with the size of 26 amino acid residues for PH691 and 22 residues for PH692. The PH activity and the localization of the respective proteins in vivo differ between cultivars. This implies that there might be different concentrations of prunasin available in the seed for amygdalin synthesis and that these differences may determine whether the mature almond develops into bitter or sweet.     

Stability of Sweet Potato Cultivars to Alternaria Leaf and Stem Blight Disease

Alternaria leaf petiole and stem blight is an economically important disease of sweet potato ( Ipomoea batatus L.) in tropical and sub-tropical environments. Published research on cultivar resistance to the sweet potato disease is limited. To evaluate cultivar reaction and stability to the disease, multi-location and replicated experiments were established in 12 environments in Uganda. Disease severity (area under disease progress curves – AUDPC), and cultivar root yield were also assessed. Significant differences (P < 0.001) in AUDPC were detected among cultivars. Mean AUDPC ranged from 46.3 (Araka Red) to 78.4 (New Kawogo) across locations and seasons and the genotypes Araka Red and Tanzania had the lowest disease values. The location and season effects accounted for 67.1% and 7.5% of the total variance of AUDPC recorded among cultivars. The ranking of cultivars based on predicted AUDPC from Additive Main Effect and Multiplicative Interactive model (AMMI) showed that the NASPOT 1, the susceptible check, and New Kawogo were most susceptible to the disease in 11 of the 12 environments. Low and stable disease was consistently recorded and predicted on NASPOT 3 and the landrace cultivars Tanzania, Dimbuca, and Araka Red across environments. These results suggest that landrace cultivars had relative stability to the disease and wide adaptation across environments. These results suggest that AMMI statistical model and other multivariate techniques can be utilized for prediction of Alternaria disease stability in these locations.     

基于发根培养体系的甘薯品种抗线虫特性鉴定研究

利用发根农杆菌诱导的甘薯发根体系,鉴定甘薯品种抗线虫的特性。试验在甘薯品种徐薯18、栗子香和鲁78066诱导的发根体系上,接种马铃薯腐烂线虫,六周后调查发根繁殖线虫情况及线虫侵染发根情况,然后评价它们的抗线虫特性。结果表明:培养六周后,线虫在徐薯18、栗子香和鲁78066发根上繁殖倍数分别为8.82,0.76和0.70;在徐薯18发根上观察到多处线虫侵入位点,在栗子香和鲁78066发根上只观察到一处线虫侵入位点;基于以上结果,鉴定徐薯18为易感线虫病品种,栗子香和鲁78066为抗线虫病品种,徐薯18和鲁78066的鉴定结果和发病地自然诱发鉴定结果相一致,栗子香不同于发病地自然诱发鉴定结果。鉴定结果表明:用不同品种的甘薯发根作鉴定其抗线虫特性,具有体系简单、直观方便、重复性好以及不受自然环境影响等优点,进一步完善可以作为植物对线虫病抗性鉴定新的体系。     

Molecular AFLP-marking of genotypes of pepper (Capsicum annuum) cultivars

The results of AFLP study of 14 Capsicum annuum cultivars are presented. Notwithstanding the known low genomic variation of large-fruited sweet pepper, AFLP analysis proved to be suitable for detecting polymorphism and genotyping pepper cultivars. Nine primer pairs were selected to allow identification of the cultivars under study. Among-cultivar polymorphism detectable with these primers was estimated at 16.5%. A characteristic AFLP pattern was obtained for each cultivar. Several cultivar-specific fragments were revealed for seven cultivars. On the basis of the AFLP data, genetic distances between cultivars were computed and a tree was constructed by means of hierarchic cluster analysis (UPGMA) with the Jacquard coefficient. It was assumed that this information is useful in breeding programs involving the cultivars examined.     

Characterization of microsatellites in wild and sweet cherry (Prunus avium L.)--markers for individual identification and reproductive processes.

Nuclear microsatellites were characterized in Prunus avium and validated as markers for individual and cultivar identification, as well as for studies of pollen- and seed-mediated gene flow. We used 20 primer pairs from a simple sequence repeat (SSR) library of Prunus persica and identified 7 loci harboring polymorphic microsatellite sequences in P. avium. In a natural population of 75 wild cherry trees, the number of alleles per locus ranged from 4 to 9 and expected heterozygosity from 0.39 to 0.77. The variability of the SSR markers allowed an unambiguous identification of individual trees and potential root suckers. Additionally, we analyzed 13 sweet cherry cultivars and differentiated 12 of them. An exclusion probability of 0.984 was calculated, which indicates that the seven loci are suitable markers for paternity analysis. The woody endocarp was successfully used for resolution of all microsatellite loci and exhibited the same multilocus genotype as the mother tree, as shown in a single seed progeny. Hence, SSR fingerprinting of the purely maternal endocarp was also successful in this Prunus species, allowing the identification of the mother tree of the dispersed seeds. The linkage of microsatellite loci with PCR-amplified alleles of the self-incompatibility locus was tested in two full-sib families of sweet cherry cultivars. From low recombination frequencies, we inferred that two loci are linked with the S locus. The present study provides markers that will significantly facilitate studies of spatial genetic variation and gene flow in wild cherry, as well as breeding programs in sweet cherry.     

Assessment of sweet potato [Ipomoea batatas (L.) Lam] for bioethanol production in southern Italy

The potential of sweet potato as an alternative crop for bioethanol production has been assessed. We evaluated the amount of soluble sugars, starch and cell wall polysaccharides in tubers of three sweet potato cultivars characterized by different pulp and peel colouration: “Yellow yam” with yellow flesh and brown peel, “White yam” with white flesh and white peel and “Orange yam” with orange flesh and brown peel. The results confirm the high concentration of carbohydrates in sweet potato tubers, especially “Yellow yam”, mainly in the form of starch (67%) and soluble sugars (26%). “Yellow yam”, which is the most widespread cultivar in Salento, appeared the best choice as biomass for bioethanol production. It is characterized by high productivity (20–40 tons/ha year). Results also suggest that “Yellow yam” cultivar has great potential as a bioethanol source in southern Italy with an estimated agroindustrial production yield higher than 2032 l/ha year.     

Reduced susceptibility to waterlogging together with high-light stress is related to increases in superoxide dismutase and catalase activities in sweet potato

We investigated the changes in antioxidative enzyme activities of two sweet potato cultivars under waterlogging and high-light conditions in the growth chamber. The activities of antioxidative enzymes were measured from leaf crude extract of sweet potato during the first five days of the treatments. Activities of superoxide dismutase and catalase were consistently increased in Taoyuan 1 sweet potato over time under waterlogging and high-light conditions. However, decreases in both superoxide dismutase and catalase activities were observed for cultivar Yongtsai under waterlogging and high-light conditions. Waterlogging, together with high-light intensity, impairs superoxide dismutase and catalase activities in the cultivar Yongtsai indicating its greater susceptibility to waterlogging and high-light stress. In contrast, the increase in activities of superoxide dismutase and catalase in Taoyuan 1 indicated its greater ability to detoxify reactive oxygen species during the treatment and ensured its reduced susceptibility to waterlogging and high-light stress. The activities of peroxidase may be inactivated by high-light treatment and, therefore, may not be associated with tolerance of sweet potato plants to waterlogging and high-light stress. Differences in susceptibility to waterlogging and high-light conditions in the leafy vegetable Yongtsai and storage root Taoyuan 1 are discussed.