Effects of Weak Light on the Ultrastructural Variations of Phloem Tissues in Source Leaves of Three-Year-Old Nectarine Trees(Prunus persica L.var. nectarina Ait.)

Leaves from three_year_old solar greenhouse nectarine trees ( Prunus persica L. var. nectarina Ait. “Zao Hong Yan”) were used as materials in this study. It was the first time that the ultrastructural characteristics of phloem tissues of source leaves were observed and compared in normal and weak light intensities using the transmission electron microscopy. Results showed that the average diameters of companion cells (CC) and sieve elements (SE) of all kinds of veins were bigger in normal than that in weak light intensity, indicating that light could influence the cell development and growth. Dense cytoplasm with abundant mitochondria, endoplasmic reticulums, multivesicular bodies, vesicles and plastids were observed in normal light intensity. On the contrary, CC with small vacuolar structures and few mitochondrias, endoplasmic reticulums were shown in weak light. Misalignment of grana thylakoid margins of nectarine leaves also was seen in weak light. The sieve pores of SEs were obstructed in weak light. Chloroplasts with numerous starch grains and few mitochondrias were noticed in the mesophyll cell (MES) surrounding the bundle sheath in weak light. The storage of starch grains appeared to result from an unbalance between photosynthate production and export of photosynthates. This observation provided a strong support to the point that most leaves export the most of assimilates in the light time. Plasmodesmal densities between SE/CC, CC/PP (phloem parenchyma cell), PP/PP and PP/BSC (bundle_sheath cell) decreased in weak light. Plasmodesmata were observed between CC/SE (NS) (nacreous_walled sieve element), PP/BSC in branch veins in normal light intensity, but not in weak light. Thus apoplasmic pathway may be the main mode of transport of assimilates in weak light, however symplasmic pathway may be the main mode of transport of assimilates in normal light intensity. These results demonstrated that the solar greenhouse nectarine trees could be adapted to the weak light via the ultrastructure variation of phloem tissues of the source leaves.

Novel in silico EST-SSR markers and bioinformatic approaches to detect genetic variation among peach(Prunus persica L.)germplasm

Because there are thousands of peach cultivars,cultivar classification is a critical step before starting a breeding project.Various molecular markers such as simple sequence repeats(SSRs)can be used.In this study,67 polymorphic primers produced 302 bands.Higher values for SI index(1.903)suggested higher genetic variability in the genotype under investigation.Mean values for observed alleles(Na),expected heterozygosity(He),effective alleles(Ne),Nei’s information index(h),and polymorphic information content(PIC)were 4.5,0.83,5.45,0.83,and 0.81,respectively.The dendrogram constructed based on Jaccard’s similarity coefficients outlined four distinct clusters in the entire germplasm.In addition,an analysis of molecular variance(AMOVA)showed that70.68%of the total variation was due to within-population variation,while 29.32%was due to variation among populations.According to this research,all primers were successfully used for the peach accessions.The EST-SSR markers should be useful in peach breeding programs and other research.

Effects of nitrogen content on growth and hydraulic characteristics of peach(Prunus persica L.) seedlings under different soil moisture conditions

A pot experiment was conducted to investigate the effects of nitrogen content [Nl （no fertilizer）, N2 （0.15 g.kg-l）, and N3 （0.3 g.kg 1）] on the growth and the hydraulic characteristics of peach seedlings under different soil moisture conditions （Wl, W2 and W3, in which the soil water content was 45% to 55%, 60% to 70%, and 75% to 80% of the field water capacity, respectively） by using a specialized high pressure flow meter with a root chamber and a coupling, which was connected to plant organs. Leaf area and leaf hydraulic conductivity （KL） increased significantly in the seedlings because of increased soil moisture and N content. KL increased with leaf area. A linear correlation was documented between KL and leaf area. KL was higher in the morning and began to decline sharply after 16：00, at which KL declined after an initial increase. Soil moisture and N content enhanced shoot （Ks） and root （Kr） hydraulic conductivities, thereby improving the low soil moisture condition to a large extent. Ks and Kr of the seedlings were reduced by 32% and 27% respectively in N~, and by 14.7% and 9.4%, respectively in N2, and both in Wb compared with the control treatment. N3 had no significant effect on Ks and Kr under similar conditions. Linear negative correlations were observed between Kr and the excised root diameter as well as between Ks and the shoot stem diameter. The shoot-to-root ratio increased with in- crease in N content. The shoot-to-root ratio in N3 was increased by 14.37%, compared with N1 in W1 as well as by 12% and 4.39% in Wz and W3, respectively. Knowledge of the effects of soil moisture and N fertilizer on hydraulic characteristics and growth is important. Our results provide basic guidelines for the implementation of water-saving irrigation and fertilization management of nursery stock.

Accumulated chilling hours during endodormancy impact blooming and fruit shape development in peach(Prunus persica L.)

Winter chill is essential for the growth and development of deciduous species. To understand the relationship between accumulated chilling hours during endodormancy and blooming and fruit shape development, we controlled chilling hours and investigated their effects on blooming date and fruit shape of peaches. The results showed that the number of days to full bloom date and the heat requirement for blooming were negatively correlated with accumulated chilling hours. Accumulated chilling hours were significantly negatively correlated with fruit shape index and fruit tip lengths, suggesting that the number of chilling hours affect the fruit shape development. Fewer accumulated chilling hours may be the major reason for longer fruit shape and protruding fruit tips. In conclusion, our results indicate specifically that decreased winter chilling hours can delay the bloom date and may lead to aberrant fruit shape development in peaches. Our study provides preliminary insights into the response of temperate fruit species to global climate change.

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。

Cloning and Expression of a cDNA Encoding Endopolygalacturonase from Feicheng Peach (Prunus persica)

Polygalacturonase (PG,EC3.2.1.15) is the key cell wall hydrolase in fruit ripening. The identification and characterization of a full length cDNA (pMT18) encoding for PG from Feicheng peach (Prunus persica (L.) Batsch cv. Feicheng) is described. The pMT18 clone is 1188 bp in length, with an open reading frame of 393 amino acids. The homology and phylogenetic analyses indicate a remarkable similarity between peach PG and other ripening related PG. And seven consensus sequences have revealed in peach PG compared to the PG from other plants. However, the profound divergence with other PG and the unique structure features suggest that peach PG probably belongs to a new evolutionary class. In RT PCR analysis, pMT18 related RNA was undetectable in leaves, and was much abundant in ripe fruits. The ripening specific expression pattern of this cDNA will be useful in investigating the roles of PG in fruit ripening and developing a transgenic peach with the improved post harvesting quality in the future.

Study on SSR Markers Linked to Flesh Color around the Stone of Prunus persica(L.) Batsch

[Objective] This study aimed to select SSR molecular markers linked to flesh color around the stone of Prunus persica （L.） Batsch. [Method] P. persica （L.） Batsch varieties Chongyanghong and Yanhong were used as parents to construct F1 orthogonal group. A total of 138 FI individuals were selected as experimental materi- als for construction of color around the stone gene pool （B1） and non-color around the stone gene pool （B2） by using bulked segregant analysis （BSA） method, molec- ular markers linked to the flesh color around the stone of P. persica （L.） Batsch were selected with SSR molecular marker technology. [Result] After selection with 256 pairs of SSR primers, three pairs of molecular markers linked to the gene con- trolling flesh color around the stone of P. persica （L.） Batsch were selected （UDP96- 003, ch04g09 and UDP97-402）. In addition, genetic distances between the three molecular markers and the gene controlling flesh color around the stone of P. persi- ca （L.） Batsch were calculated, which were 16.7, 10.1 and 17.0 cM, respectively. [Conclusion] This study laid the foundation for further selection of co-dominant molecular markers with closer genetic distance.

Molecular cloning,identification,and chromosomal localization of two MADS box genes in peach(Prunus persica)

MADS box proteins play an important role in floral development. To find genes involved in the floral transition of Prunus species, cDNAs for two MADS box genes, PpMADS1 and PpMADSIO, were cloned using degenerate primers and 5＇- and T-RACE based on the sequence database of P. persiea and P. duleis. The full length of PpMADS1 cDNA is 1,071 bp containing an open reading frame （ORF） of 717 bp and coding for a polypeptide of 238 amino acid residues. The full length of PpMADSIO cDNA is 937 bp containing an ORF of 633 bp and coding for a polypeptide of 210 amino acid residues. Sequence comparison revealed that PpMADS1 and PpMADSIO were highly homologous to genes API and PI in Arabidopsis, respectively. Phylogenetic analysis indicated that PpMADS1 belongs to the euAP1 clade of class A, and PpMADSIO is a member of GLO/PI clade of class B. RT-PCR analysis showed that PpMADS1 was expressed in sepal, petal, carpel, and fruit, which was slightly different from the expression pattern ofAPl; PpMADS10 was expressed in petal and stamen, which shared the same expression pattern as PI. Using selective mapping strategy, PpMADSI was assigned onto the Binl：50 on the G1 linkage group between the markers MCO44 and TSA2, and PpMADSIO onto the Bin1：73 on the same linkage group between the markers Lap- 1 and FGA8. Our results provided the basis for further dissection of the two MADS box gene function.

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.

Characterization and Expression of Ammonium Transporter in Peach (Prunus persica) and Regulation Analysis in Response to External Ammonium Supply

As the preferred nitrogen(N)source,ammonium(NH_(4)^(+))contributes to plant growth and development and fruit quality.In plants,NH 4+uptake is facilitated by a family of NH_(4)^(+) transporters(AMT).However,the molecular mechanisms and functional characteristics of the AMT genes in peach have not been mentioned yet.In this present study,excess NH_(4)^(+) stress severely hindered shoot growth and root elongation,accompanied with reduced mineral accumulation,decreased leaf chlorophyll concentration,and stunned photosynthetic performance.In addition,we identified 14 putative AMT genes in peach(PpeAMT).Expression analysis showed that PpeAMT genes were differently expressed in peach leaves,stems and roots,and were distinctly regulated by external NH_(4)^(+) supplies.Putative cis-elements involved in abiotic stress adaption,Ca^(2+) response,light and circadian rhythms regulation,and seed development were observed in the promoters of the PpeAMT family genes.Phosphorylation analysis of residues within the C-terminal of PpeAMT proteins revealed many conserved phosphorylation residues in both the AMT1 and AMT2 subfamily members,which could potentially play roles in controlling the NH 4+transport activities.This study provides gene resources to study the biological function of AMT proteins in peach,and reveals molecular basis for NH_(4)^(+) uptake and N nutrition mechanisms of fruit trees.

Volatiles from <i>Prunus persica</i>Flowers and Their Correlation with Flower-Visiting Insect Community in Wanbailin Ecological Garden, China

Object: To investigate the VOCs from living Prunus persica flowers of different branches and their correlation with floral insects. Special, dominant and 20 VOCs were analysed from living Prunus persica flowers captured by closely and circularly headspace way in adsorbent tubes and ATD-GC/MS on 29 April in Wanbailin Ecological Garden, China. VOCs from high altitude tree are more than low altitude in sunny site, and floral volatile constituents from upslope branches are less than downslope of the same tree on high altitude. Special floral VOCs were alpha-dimethyl-benzenemethanol, isopropyl palmitate, ethylbenzene, p-xylene, acetophenone, 3-ethyl-2-methyl-Heptane on sunny slope, and propylene glycol, decanal, hexadecane on shady slope. Dominant VOCs founded during 8 temporal quanta were toluene, hexane, 2-ethyl-1-hexanol, dodecane, pentadecane. Floral VOCs’ number from sunny slope was significantly negative correlated with flower-visiting insect community richness, abundance, diversity on sunny or shady slope, which from shady slope was significantly positive correlated with flower-visiting insect community parameters on both slopes tried dividing insects visiting floral branches from Prunus persica in sunny site with n/2 + 1 or n/2 - 1, and shady site with n/2 before sampled volatiles day. On sampled volatiles day, 2-ethyl-1-hexanol from sunny slope was significantly positive correlated with flower-visiting insect community parameters on shady slope (P Prunus persica on sunny slope, and even floral branches kept on shady slope.

防除杏树(Prunus armeniaca L.)冰核细菌药剂筛选及花期防霜效果

采用vali结冻法和含菌平板培养法，从9种供试药剂中筛选出1号、2号、3号、5号、7号5种对INA细菌触杀及破坏冰蛋白作用的药剂。将5种筛选的药剂于日光温室和田间进行药剂防霜试验研究，结果表明，日光温室霜冻温度为-4℃时，5种药剂中3号、7号防霜效果显著，分别为47．05％～67．74％和49．44％～69．33％。3号、7号分别提高座果率12．25％～14．83％和4．69％～11．36％，与对照相比差异达显著水平。大田温度为-6．5℃时，5种药剂中3号的防霜效果为21．80％，提高座果率9．17％。与对照相比达显著水平。

半干旱黄土丘陵区天然次生灌木山桃(Prunus davidiana)与山杏(Prunus sibirica L.)叶片气体交换参数日动态差异

以半干旱黄土丘陵区5年生天然次生灌木山桃(Prunus davidiana)及山杏(Prunus sibirica L.)作为研究材料,系统比较了两树种叶片气体交换参数的日变化特征,分析了其光合作用和蒸腾作用与环境因子的关系。结果表明:山桃叶片气体交换参数日变化特征与山桃有所差异,山桃除蒸腾速率(Tr)外其它生理参数呈单峰曲线,山杏的日变化类型均呈双峰曲线。两树种光合速率(Pn)在下午明显下降,其原因主要是受到非气孔限制。山桃Pn的日均值((7.64±3.69)μmo.lm-2.s-1)比山杏((5.29±2.97)μmo.lm-2.s-1)高出46%,Tr的日均值((2.21±1.02)mmo.lm-.2s-1)比山杏((1.58±0.57)mmo.lm-.2s-1)高出40%左右,水分利用效率(WUE)的日均值相差不大,分别为(2.89±1.52)μmo.lmmol-1,(2.54±1.37)μmo.lmmol-1。多元回归及相关分析表明,影响光合作用与蒸腾作用的最重要因子是光合有效辐射强度,其次是大气CO2浓度;光合作用与蒸腾作用参数之间也有明显的相关性。结论:山桃与山杏表现出具有较高光合速率,较低蒸腾速率和较高水分利用效率的生理特征,因而在半干旱黄土丘陵区都有较好引种栽培与开发利用潜力。

采后包装及钙处理对‘豫甜’桃(Prunus persica)果实品质的影响

以'豫甜'桃为试验材料,研究不同包装处理室温贮藏及采后钙处理低温贮藏对其果实品质的影响.结果表明,在室温贮藏条件下,聚乙烯膜包装袋中加入KMnO4(乙烯吸收剂)的贮藏效果明显优于其它2种处理.与对照相比,果实的呼吸速率减小了5 0mg·kg-1·h-1,果实硬度增加了2 6kg·cm-2,Vc含量增加了10μg·g-1,可溶性酸含量增加了0 07g·kg-1,可溶性固形物含量增加了2 1g·kg-1,总糖含量增加了2 8g·kg-1;经ρ为4%的CaCl2溶液处理后,装入加有KMnO4(乙烯吸收剂)的聚乙烯膜包装袋中,在0～5℃的低温下贮藏效果最好,与对照相比:果实的呼吸速率减小了1 0mg·kg-1·h-1,果实硬度增加了2 1kg·cm-2,Vc含量增加了1 3μg·g-1,可溶性酸含量增加了0 17g·kg-1,可溶性固形物含量增加了-0 25g·kg-1,总糖含量增加了0 5g·kg-1;综合比较认为采后钙处理再低温贮藏能较好地降低桃果实的呼吸速率,保持果实的硬度,抑制Vc的降解,较长时间地维持果实的营养成分,保持其品质不大幅度下降.

不同来源中国李(Prunus salicina L.)的多样性与近缘种关系

【目的】中国李资源丰富、分布广泛。更好地明晰不同来源中国李栽培品种的多样性、遗传结构差异以及与同域近缘种的关系,将有利于明确中国李驯化扩散历程以及近缘种在栽培驯化过程中的作用,促进中国李地方品种资源的深入挖掘和新品种的选育。【方法】利用均匀分布于基因组的22对SSR分子标记,采用荧光毛细管电泳检测技术对48份种质进行基因分型,其中包括38份不同来源的中国李种质、10份变异类型或近缘种。通过GenAlEx 6.41软件评估22对SSR引物的多态性,对参试种质按不同来源分析遗传多样性;利用NTSYS-pc 2.1软件构建48份材料的树状聚类分析图;并根据贝叶斯模型的Structure 2.2软件分析不同居群间的遗传结构差异。【结果】基于48份供试材料的数据,22对SSR引物等位变异范围为3—21个,平均每个位点检测到13.54个;总共检测到298个等位变异,其中有51.8%的等位变异属于稀有等位变异。在不同居群间进行比较,根据平均有效等位变异(Ne)、平均Shannon’s多样性指数(I)、观察杂合度(Ho)和期望杂合度(He)可以看出,南方品种群的多样性最高,其次为东北品种群;而杏李的多样性最低,且明显低于华北品种群。通过分子方差分析,认为中国李的多样性有69%的遗传变异来源于居群内,仅有31%的遗传变异来源于居群间。基于遗传分化系数和Nei’s遗传距离的数据比较,认为不同居群间存在显著的遗传分化,同时不同地理来源种质间存在适当的基因交流。树状聚类分析暗示国外育成品种与我国南方品种群具有较近的亲缘关系;而华北品种群与杏李关系密切;东北品种群与乌苏里李关系紧密。群体结构分析可以将栽培中国李种质资源划分为南方小果脆肉品种群、南方大果品种群(包括国外育成品种)、华北品种群和东北品种群。【结论】我国南方地区中国李的多样性最为丰富,按东北品种群、国外品种群、华北品种群顺序依次降低。东北品种群为了提高适应性融入了乌苏里李基因;杏李是从华北品种群中高度驯化后的特化类型,且该类型通过无性繁殖保存了其高度杂合性状态。我国南方江浙地区的大果型种质对国外育成品种起着重要作用。

Analysis of Genetic Relationships in Prunus domestica L. in Xinjiang Using ISSR Markers

[Objective] This paper aimed to explore the genetic relationships among different types of Prunus domestica L. in Xinjiang. [Method] The inter-simple se- quence repeat （ISSR） markers were applied to analyze the genetic diversity and relationships among 30 individual plants from 5 types of P. domestica germpiasm resources in Xinjiang. [Result] A total of 317 bands were amplified by 16 selected IS- SR primers. Among the amplified bands, there were 246 polymorphic bands, accounting for 77.60% of the total. The Nei＇s gene diversity index （H） of individuals was 0.266 6. The average Shannon＇s information index （I） of individuals was 0.399 1. And most of the genetic similarity coefficients ranged from 0.555 2 to 0.996 8. It is indicated that the P. domestica germplasm resources have a certain genetic diversity in Xinjiang. The cluster analysis showed that, at the genetic similarity coefficient of 0.719, the 30 individuals were divided into 3 major groups, including a group of introduced European plum varieties, a group of Tacheng Smoked Plum and Tacheng Binzi and a group of Jiashi Smoked Plum and Wild European Plum. While at the genetic similarity coefficient of 0.949, Jiashi Smoked Plum and Wild European Plum were divided into two small groups. [Conclusion] There are very close genetic relationships between Jiashi Smoked Plum and Wild European Plum, and among the introduced European plum varieties, Tacheng Smoked Plum and Tacheng Binzi.

The Flowering Biology of Plum(Prunus domestica L.) in Aksu Region, Xinjiang

[Objective] The aim of this study was to understand the flowering biological characteristics of different varieties Prunus domestica L. in Aksu Jiamu Experi- ment Station. [Method] Three varieties of plum as Prunus domestica L. cv. ＇French＇, Prunus domestica L. cv. ＂Victoria＇ and Prunus domestica L. cv. ＂Stanley＇ were the research subjects. The phenophases of blooming, and the morphological and developmental characteristics of floral organs were observed. The amount and viability of pollen and the stigma receptivity were measured. [Result] Three varieties of plum all blossomed in early April, and the florescence had lasted for 9-10 d. The average number of anthers was 28.48%. The average number of pollen grains in each flower was 28 700.0. The pollen germination rate was 27.4%. 86.75% of the flowers were medium-styled or long-styled. There was no significant difference in the petal shape, color, anther number, calyx color, and flower ovary among the three varieties of plum. The stigma receptivity was strongest on the first day of flowering, and then dropped gradually. Therefore, the flowers of plum were manual pollinated on the first day of flowering. The duration time of stigma receptivity of Prunus domestica L. cv. ＇Victoria＇ was longer than the other cultivars, the duration time of stigma receptivity was about 5 d. [Conclusion] The pollen number and pollen germination rate of Prunus domestica L. cv. ＇Stanley＇ were higher than the other cultivars, which be considered the most suitable pollinizer for plum. In contrast, the complete flower rate of Prunus domestica L. cv. ＇French＇ and Prunus domestica L. cv. ＇Victoria＇ was relatively high, but the pollen number and pollen germination rate of Prunus domestica L. cv. ＇French＇ and Prunus domestica L. cv. ＇Victoria＇ were lower than Prunus domestica L. cv. ＇Stanley＇, which are not suitable to use as a pollinizer for plum.

离体条件下桃（Prunuspersica）脱病毒技术的改进

为提高离体条件下挑脱病毒的效果，本研究比较了茎尖分生组织培养和微型嫁接两种脱病毒技术。采用倒“Ｔ”型和“孔穴”嫁接法，将“红港”嫁接在“ＣＴ２６９２”上，其成活率分别为１８．２％和４９．５％。试验还表明，“红港”的茎尖分生组织的分化率取决于分生组织块的大小。供试３个桃品种“红港”、“Ｍａｙｏｒｅｓｔ”和“Ｓｕｎｃｒｅｓｔ”的茎尖分生组织在本试验所筛选出的改进培养基上的分化率最高，该培养基含Ａｎｄｅｒｓｏｎ矿质成份（１９７８），Ｓｐａｔａ维生素（１９６９）。激素配比为０．２ｍｇ／１ＢＡ，０．０１ｍｇ／１ＩＢＡ和０．１ｍｇ／１ＧＡ。关键词：

两种抑制剂对肥城桃(Prunus persica)多酚氧化酶抑制类型的研究

本文用丙酮和硫酸铵沉淀的方法将肥城桃 (Feichengpeach)多酚氧化酶部分纯化 ,纯化倍数为 5 1 1倍。研究了二乙基二硫代氨基甲酸钠和硫脲对该酶活性的抑制类型。

紫叶桃(Prunus persica f. atropurpurea)的愈伤组织诱导和培养

紫叶桃是重要的园林彩叶树种,叶色美丽,观赏期长,具有很高的园林应用价值。以紫叶桃的叶片和嫩茎段为外植体,用不同浓度生长调节物质进行愈伤组织诱导试验,建立紫叶桃的再生体系。结果表明,诱导愈伤组织时,MS+2 mg/L BA+1 mg/L 2,4-D对叶片诱导效果最佳,其诱导率达80%;MS+1 mg/L BA+1 mg/L 2,4-D对茎段诱导效果最佳,其诱导率达100%。在MS+1 mg/L BA+1 mg/L NAA培养基上愈伤组织能直接分化出不定芽。