ISSR-Based Molecular Characterization of an Elite Germplasm Collection of Sweet Potato （Ipomoea batatas L.） in China

To determine the genetic diversity and population structure of sweet potato accessions cultivated in China, and to establish the genetic relationships among their germplasm types, a representative collection of 240 accessions was analyzed using inter-simple sequence repeat （ISSR） markers. The mean genetic similarity coefifcient, Nei’s gene diversity, and shared allele distance of tested sweet potato accessions were 0.7302, 0.3167 and 0.2698, respectively. The 240 accessions could be divided into six subgroups and ifve subpopulations based on neighbor-joining （NJ） clustering and STRUCTURE results, and obvious genetic relationships among the tested sweet potato accessions were identiifed. The marker-based NJ clustering and population structure showed no distinct assignment pattern corresponding to lfesh color or geographical ecotype of the tested sweet potato germplasm. Analysis of molecular variance （AMOVA） revealed small but signiifcant difference between white and orange-lfeshed sweet potato accessions. Small but signiifcant difference were also observed among sweet potato accessions from the Southern summer-autumn sweet potato region, the Yellow River Basin spring and summer sweet potato region and the Yangtze River Basin summer sweet potato region. This study demonstrates that genetic diversity in the tested sweet potato germplasm collection in China is lower than that in some reported sweet potato germplasm collections from other regions. Pedigree investigations suggest that more diverse Chinese sweet potato varieties should be formed by broadening the selection scope of breeding parents and incorporating the introduced varieties into future breeding programs.     

Genetic Diversity Analysis of Faba Bean （Vicia faba L.） Based on EST-SSR Markers

Faba bean (Viciafaba L.), one of the most important legumes in the world, evolved different types of cultivars due to its partial cross-pollination. The development of simple sequence repeat (SSR) markers from expressed sequence tags (EST) provided a useful tool for investigation of its genetic diversity. The purpose of the present study was to investigate the genetic diversity of faba bean from China and Europe using EST-SSR markers. 5 031 faba bean ESTs from the NCBI database were downloaded and assembled into 1148 unigenes. A total of 107 microsatellites in 96 unigenes were identified, indicating that merely 8.36% of sequences contained SSRs. The most abundant SSR within faba bean was tri-nucleotide repeat motif, and among all the tri-nucleotide repeats, the motif AAG/CTT was the most abundant type. Based on these results, 11 EST-SSR markers were used to assess the genetic diversity of 29 faba bean cultivars from China and Europe with two to three alleles per locus. The polymorphism information content value ranged from 0.0644 to 0.4278 with an average of 0.2919. Principal coordinate analysis (PCA) and phylogenetic clustering based on these 11 EST-SSR markers distinguished these cultivars into different groups. The results indicated that faba bean in China had a narrow genetic basis, and the additional sources of genetic cultivars/accessions should be introduced to enhance the genetic variability. The results of this study proved that the EST-SSR marker is very effective in evaluation of faba bean germplasm.     

Mapping of Mutant Gene prbs Controlling Poly-Row-and-Branched Spike in Barley （Hordeum vulgare L.）

A row-type mutant of barley named poly-row-and-branched spike (prbs) was previously obtained from a two-rowed cultivar Pudamai-2 after treated by inflorescence soaking in maize total DNA solution.The mutant produces branched spikes with irregular multiple rows.Genetic analysis indicated that the mutant phenotype was caused by a recessive gene prbs,and the PRBS locus had a recessive epistatic effect on an independent locus (denoted as Vrsx) conferring the variation of two-rowed spike vs.six-rowed spike.This study aimed to map PRBS as well as Vrsx using simple sequence repeats (SSR) markers.We developed an F2 population from a cross between the prbs mutant and a six-rowed cultivar Putianwudu for the gene mapping.As the two target loci interacted to result in a segregation ratio of two-rowed type:sixrowed type:prbs=9:3:4 in the population,we adopted a special strategy to map the two loci.PRBS was mapped between SSR markers HvLTPPB and Bmag0508A on the short arm of chromosome 3H,with distances of 24.7 and 14.3 cM to the two markers,respectively.Vrsx was mapped between SSR markers Bmag0125 and Bmag0378 on chromosome 2H,with distances of 6.9 and 15.3 cM to the two markers,respectively.This suggests that Vrsx should be the known locus Vrsl,which predominantly controls row-type variation in barley cultivars,and PRBS is a new locus related to the row type of spikes in barley.     

A Genetic Linkage Map of Kenaf （Hibiscus cannabinus L.） Based on SRAP,ISSR and RAPD Markers

Kenaf (Hibiscus cannabinus L.) is one of the most economically important crops for non-wood fiber production. The objective of this study was to establish a genetic linkage map of kenaf with higher density of molecular markers. A semi-wild variety Ga42 and a cultivar Alain kenaf were used as parents to construct an F₂ population consisting of 155 plants. The genetic linkage map comprising 134 marker loci was constructed, including 65 sequence-related amplified polymorphism (SRAP), 56 inter-simple sequence repeat (ISSR), and 13 randomly amplified polymorphic DNA (RAPD) markers. This map spans 2 108.9 cM and contains 20 linkage groups with an average marker density of 15.7 cM between the adjacent markers.     

ISSR Analysis on Genetic Diversity of Local Varieties of Chinese Hu mulberry（Morus L.）

[Objective] The aim was to study on the genetic diversity of local varieties of Chinese Hu mulberry （Morus L.）. [Method] The genetic diversity of 141 copies of Hu mulberry varieties was analyzed by ISSR molecular markers. [Result] 12 ISSR primers had amplified a total of 90 amplified,of which 57 bands were polymorphic,and the polymorphic rate was 63.33%. The genetic similarity coefficients of 141 Hu mulberry germplasm resources varied from 0.633 3 to 1.000 0 with the average of 0.483 35,indicating that there was difference on genetic diversity among different varieties of Hu mulberries. A dendrogram of all 141 Hu mulberry varieties based on the genetic similarity coefficients using ISSR molecular markers was generated by UPGMA cluster method. Clustering of the 141 Hu mulberry varieties did not correspond with the conventional classification involving differences in style,leaf,branch,fruit and other morphological or agronomical characters. [Conclusion] Four subgroups clearly represented the genetic relationships in the 141 accessions which were benefit for the variety improvement and germplasm resource conservation.     

基于SSR标记的甜瓜品种（系）DNA指纹图谱库的构建

【目的】建立甜瓜品种的DNA指纹图谱数据库,实现对甜瓜品种进行快速、准确的鉴定。【方法】应用SSR分子标记技术,首先利用20份具有代表性的甜瓜品种（系）筛选SSR引物,然后对105份不同甜瓜品种（系）进行指纹图谱的构建。【结果】从1 219对SSR引物中筛选出18对引物为105份材料形成了多态性的指纹图谱,其中每对引物可以检测到4-14条数目不等的多态性条带,平均为9条;多态性信息含量（PIC）平均为0.68,变化范围为0.55-0.82。105份材料间的相似系数为0.70-0.99。利用这18对SSR核心引物构建的指纹图谱库能够有效区分所有供试材料,并且为每份材料建立了一份独特的指纹图谱。【结论】SSR标记适于构建甜瓜品种  （系）的DNA指纹图谱库,可为甜瓜品种鉴定提供依据。     

基于SSR分子标记的福建百香果品种（系）鉴定及指纹图谱构建

【目的】基于SSR分子标记鉴别福建百香果品种的遗传多样性,构建福建百香果品种的分子指纹图谱。【方法】基于转录组测序,开发西番莲SSR分析标记,并筛选出15个重复性好、多态性高的分子标记用于17个福建百香果品种（系）鉴定及遗传多态性分析,构建百香果品种（系）的SSR分子指纹图谱。【结果】利用MISA软件对1 kb以上的24 319条西番莲（Passiflora caerulea L.） Unigene进行搜索,于8 742条Unigene上检测出11 385个SSR位点,出现频率为46.82%,平均分布距离为7.15 kb。单核苷酸、二核苷酸和三核苷酸分别占总SSR的63.72%、20.40%和14.28%,为数量较大的优势重复基序,其优势重复基元分别为A/T、 AG/CT和AAG/CTT。通过Primer 3.0共获得出28 257对SSR引物。从26对有效扩增引物中选择重复性好的15对引物,对17份百香果品种（系）进行多态性验证分析。15对SSR引物共产生235条多态性条带,PIC平均值为0.95。利用UPGMA进行聚类分析并作图,在遗传距离0.765处,可将17个品种（系）分为7个...     

Molecular Related Indexes Assessment and Traits Correlation Analysis of Turbot（Scophthalmus maximus L.） by Using SSR Marker Correlation Coefficient in Turbot

Five molecular related indexes： MOL, SIM, d2, H0and PIC of 15 turbot parent pairs were estimated by using 10 SSR loci, which were used in correlation analysis with growth traits, DIL and DIW, of family filial from those 15 parent pairs.DIL and DIW were regressed on the MOL, SIM, d2, H0and PIC. Results showed MOL of five SSR loci（12, 17, 24, 81 and 85） and SIM of five loci（17, 21, 24, 81and 85） all shared significant positive correlation with DIL（r=0.482, P=0.035 and r=0.479, P=0.035, respectively）; H0of six SSR loci（11, 17, 21, 24, 26 and 85） had significant positive correlation with DIW（r=0.551, P=0.017）; PIC of two SSR loci（9and 26） had significant positive（r=0.519, P=0.024） correlation with DIL, while that and of four loci（17, 24, 27 and 85） had significant negative correlation（r=-0.519,P=0.024）, with DIL. This present study suggested that filial growth expression could be predicted by using molecular related indexes in turbot breeding practice, and the accuracy of prediction depends on more SSR loci, especially associated with QTL.     

Molecular Identification and Cultivar Fingerprints of Prunus persica (L.) Batsch Germplasms

[Objective] The aim was to study the molecular identification and cultivar fingerprints of Prunus persica (L.) Batsch germplasms.[Method] Sixty peach genotypes,representing China common local cultivars and European samples were screened by microsatellites (simple sequence repeats,SSRs) and Inter-Simple Sequence Repeat (ISSR) markers.[Result] 26 reproducible bands were amplified by Nine SSR primers,and 24 of which were polymorphic; 236 bands were amplified by 30 ISSR primers,and 113 of which were polymorphic.31 genotypes were discriminated with 1-3 distinct polymorphic bands generated from the primers ISSR and SSR.Seven cultivar-specific ISSR fragments and two SSR unique alleles obtained from this study were available to be converted into Sequence Characterized Amplified Region (SCAR) markers.The genetic similarity coefficient (GS) estimated from these molecular data averaged were 0.939 (ranged from 0.856 to 0.983) for ISSR and 0.646 (ranged from 0.240 to 1.000) for SSR,respectively.The combined grouping association indicated that most local Chinese peach cultivars and exotic accessions were clustered together.This could be related to the mode of introduction and maintenance of the peach cultivars involving limited foundation germplasm,exchange of cultivars between plantations,and periodic development of new recombinant cultivars following sexual reproduction.[Conclusion] The results obtained in this work would help to improve the conservation,molecular identification and management of peach germplasm in breeding.     

SSR方法标记桃[Prunus persic(L.)Batsch]果肉近核色素(英文)

[目的]利用 SSR 分子标记法标记桃(Prunus persic (L.) Batsch)果肉近核色素。[方法]以"重阳红"与"燕红"2 个桃品种为亲本构建正交 F1群体,选取其中138株后代作为标记群体,采用分离群体分组分析(bulked segregate analysis,BSA)法,将果肉近核色素分为"有"和"无"2个基因池,应用SSR分子标记技术寻找与桃果肉近核色素性状基因连锁的分子标记。[结果]通过对256对引物的筛选,获得了3对与控制桃果肉近核色素性状基因连锁的分子标记,即 UDP96-003、ch04g09 和 UDP97-402,同时计算得到这 3 个标记与桃果肉近核色素性状基因的遗传距离分别为16.7、10.1和17.0 cM。[结论]该研究为进一步筛选遗传距离更近的共显性分子标记奠定了基础。     

SSR方法标记桃果肉近核色素

[目的]利用SSR分子标记法标记桃(Prunus persica(L.)Batsch)果肉近核色素。[方法]以"重阳红"与"金保"2个桃品种为亲本构建正交F1群体,选取其中138株后代作为标记群体,采用分离群体分组分析(bulked segregant analysis,BSA)法,将果肉近核色素分为"有"和"无"2个基因池,应用SSR分子标记技术寻找与桃果肉近核色素性状基因连锁的分子标记。[结果]通过对256对引物的筛选,获得了3对与控制桃果肉近核色素性状基因连锁的分子标记,即UDP96-003、ch04g09和UDP97-402,同时计算得到这3个标记与桃果肉近核色素性状基因的遗传距离分别为16.7、10.1和17.0 cM。[结论]该研究为进一步筛选遗传距离更近的共显性分子标记奠定了基础。     

桃实生树不同节位叶绿素、可溶性蛋白质的动态变化

对大久保桃的2年生自然实生树不同节位叶片的叶绿素含量、叶片和韧皮部可溶性蛋白质含量进行测定。结果表明:46~50节叶片叶绿素和韧皮部可溶性蛋白含量均发生明显变化,是桃实生树生理状态发生变化的临界点,大久保桃实生树的童期结束于46~50节,成年营养生长期开始于51~55节。     

桃(Prunus persica (L.) Batsch.)品种核心种质的构建与评价

为构建桃品种核心种质,通过对56份桃(Prunus persica(L.) Batsch.)初级核心种质的形态农艺性状数据(MOR)和SSR等位基因数据的分析,研究了不同聚类取样方法和完全随机取样方法下9种取样比例的遗传多样性指数、保留比例及各频率段等位基因的丢失比例。结果表明:聚类取样的方法优于完全随机取样,并以在80%的取样比例下MOR结合SSR数据聚类取样的效果最好,利用此方案构建的桃品种核心种质共包括45份材料,该核心种质的基因遗传多样性指数最高,保留了初级核心种质100%的形态农艺性状和96.6%的SSR等位基因,在出现频率低于0.05的等位基因中共丢失了2个等位变异,保留了出现频率在0.05~0.10的所有等位基因;利用6个数量性状对所构建的核心种质的代表性检测表明所构建的核心种质很好地代表558份桃原始种质的遗传变异。     

水杨酸对大久保桃花及幼果生长的影响

[目的]研究水杨酸(SA)对大久保桃花授粉和幼果发育的影响。[方法]以大久保桃花粉和幼果为试材,研究水杨酸对花粉萌发、花粉管伸长和幼果纵横径生长的影响。[结果]0.0020、.020 mmol/L SA对花粉萌发有促进作用,而0.200 mmol/L SA处理的花粉萌发率明显低于对照;0.002 mmol/L SA处理其花粉管显著高于对照,起到了促进花粉管伸长的作用,0.200 mmol/L SA则抑制了花粉管伸长;0.002、0.0200、.200 mmol/L SA均对大久保桃幼果的生长存在不同程度的抑制作用,且随着SA浓度的增大抑制作用增强。[结论]不同浓度SA对大久保桃花及幼果生长存在不同影响。     

关中地区温室油桃标准化栽培技术研究

针对关中地区油桃温室栽培中存在的定植密度不统一、扣棚期把握不准、草苫覆盖时间有误、产量低、品质差等问题,通过一系列标准化栽培技术的试验,提出了温室油桃的标准化栽培技术,这就是定植株行距为150 cm×200 cm;扣棚时期掌握在12月下旬;在温室管理上,晴天草苫揭开、覆盖时间分别为8:00和16:00时,阴天分别为10:00和14:00;并且在7月上旬至8月上旬用15％多效唑可湿性粉剂200倍稀释液进行全株喷雾2次,以利于油桃的发芽分化.     

观赏桃林地土壤物理特性及其水分生态效益

[目的]研究桃花林下土壤水分物理特性和水分生态效益,为桃林的种植管理及发展提供理论依据。[方法]以南宁青秀山风景区桃花岛林分土壤为对象,研究不同土层和不同土壤剖面的厚度、土壤容重、最大持水量、毛管持水量、最小持水量、毛管孔隙度、非毛管孔隙度和总孔隙度。[结果]与一般土壤物理性质标准相比,桃林地整体表层土壤略紧实,土壤孔隙度在良好范围内,水–气关系协调。在0~1 m土层,土壤持水能力随土层深度的增加而降低。0~1 m土层桃花林地总持水量为4 601.3 m3/hm~2;桃花岛的土壤储水总量为62 117.6 m3,采用效益替代计算,桃花岛土壤水分生态效益总货币价值为74 541.12元。[结论]林地土层深度对土壤孔隙度状况及持水性能有一定的影响,桃花林地具有一定的水分生态效益。     

短时高温打破早露蟠桃花芽休眠效应研究

以4年生早露蟠桃的1年生枝条为试材,研究40℃、45℃、50℃3个梯度高温短时间处理对早露蟠桃花芽萌芽率以及花芽和枝皮内O2-含量、MDA含量的影响,探讨短时高温处理对桃花芽自然休眠的调控作用。结果表明:12月21日各短时高温处理,均不同程度的解除花芽休眠,早露蟠桃枝皮及花芽内O2-含量、MDA含量的影响,因处理温度和处理持续时间长短的不同而异。其中50℃3 h处理效果最好,其枝皮和花芽内MDA含量以及O2-含量均极显著高于对照。     

雨花2号桃离体微繁殖技术研究

以桃品种雨花2号春季嫩梢茎段为外植体,通过外植体消毒方法的筛选,以及腋芽诱导、腋芽增殖和生根培养基的筛选,以建立该品种的快繁体系,并解决桃离体快繁过程中常见的玻璃化和黄化问题.研究结果表明:最佳的外植体消毒方法为先以75.00%酒精浸润20 s,再用0.10% HgCl2 0.01%吐温对外植体表面消毒8 min;LP 6-BA 0.80 mg/L IBA 0.30 mg/L最利于腋芽萌发;LP 6-BA 1.50 mg/L IBA 0.20 mg/L的继代增殖培养基上4周芽增殖倍数达3.5～4.0,且植株健壮;适宜生根培养基为MS IAA 1.50 mg/L.同时,研究发现,在继代培养基中添加0.20 mg/L GA3可使黄化苗转绿,培养基中Ca2 浓度增加至0.729 mmol/L可以有效地抑制和消除玻璃化现象,培养基中使用6.50 g/L琼脂粉也可抑制玻璃化苗的产生.