施用炭化苹果枝粉末对平邑甜茶生长及根系构型的影响

选取冬季修剪下来的‘红富士’苹果枝条,分别在400、600 和700 ℃下厌氧炭化后粉碎过筛,按照1%和2%的质量比施入2 年生盆栽平邑甜茶的盆土中,调查平邑甜茶光合性能、植株生长量、根系活力和根系构型参数等。结果表明,3 种温度热解制备的炭化苹果枝粉末明显提高平邑甜茶叶片净光合速率、株高、干径和植株干质量,明显增加根活力、根系总长度、根系直径、根系表面积和根系体积,并且明显增大根系分形维数,使根系结构复杂化;在400 ~ 700 ℃的范围内,随着炭化温度升高,炭化苹果枝粉末对平邑甜茶的作用效果也逐渐升高;土壤施用2%的炭化苹果枝粉末的作用效果大于施用1%的处理。     

Cre/loxp系统的构建及无选择标记转基因苹果植株的获得

从‘霞晖8号’桃中克隆了一个定位于第4条染色体上的钾转运体基因PpeKUP5,该基因编码625个氨基酸,具有10个跨膜结构域;PpeKUP5主要在根部表达,其次是叶和茎中,花和果实中的表达量极低;ABA、重金属Cr和Zn处理均显著诱导其在桃幼苗各组织中的表达,其中Cr处理最为显著,高钾胁迫及重金属Cu处理显著降低了其在根部的表达水平;细菌互补试验表明PpeKUP5具有吸收外界K+（KCl或K2SO4）的功能,且在偏中性pH值条件下最为显著。本研究表明PpeKUP5是一个主导桃树根部K+吸收的钾转运体,并可能在桃树适应高钾及重金属Cr、Zn和Cu等胁迫处理和ABA 响应中起着重要作用。     

苹果种质资源果实轮纹病抗性的评价

利用5个不同来源的苹果轮纹病菌株,对279份苹果种质资源的果实抗病性进行室内接种鉴定。结果表明：不同种质资源在果实的发病率、潜伏期和病斑大小上均存在极显著差异;同一种质资源分别接种5种轮纹病菌,在发病率、潜伏期和病斑大小上也存在显著差异。对抗病性指标进行相关性分析,多数菌株的各个抗病指标间都存在显著相关性。通过综合抗性筛选,发现‘珍宝’、‘金沙依拉姆’和‘红玉’为高抗材料;‘詹姆斯格里斯’、‘红夏’‘耍红’、‘伊朗桃苹’‘超等蔷薇’和‘极早红’为高感材料。     

β–1,3葡聚糖酶基因转化提高苹果对斑点落叶病的抗性

为提高苹果抗病性,利用根癌农杆菌介导的叶片转化法,将带有NPTⅡ筛选基因、GUS标记基因及β–1,3葡聚糖酶目的基因质粒导入‘富士’和‘嘎拉’苹果。具有卡那霉素(Kan)抗性的转化株系,经GUS组织化学染色及PCR扩增检测,得到17个‘嘎拉’阳性株系和11个‘富士’阳性株系。选取‘嘎拉’和‘富士’各3个阳性株系进行Southern blot检测,结果表明外源目的基因已整合到所试转化株系中。选取‘嘎拉’及‘富士’各5个阳性株系进行半定量RT-PCR检测,除1个‘富士’株系没有条带外,其余株系均有阳性条带,且各条带的明亮清晰程度有差别,说明不同转基因株系中目的基因的表达量有差异。转化植株离体叶片接种苹果斑点落叶病菌进行抗病性表型检测结果证实,‘嘎拉’10个转化株系中8个株系表现抗病,7个‘富士’转化株系中2个株系表现一定的抗病性,抗病性的增强与目的基因的表达水平有关。     

苹果糖转运蛋白TMT基因的表达及其与糖积累的关系

利用苹果基因组筛选液泡膜单糖转运蛋白TMT 家族基因,通过qRT-PCR 探索它们在苹果各器官组织中的表达特性,并分析其表达与果实糖积累的关系。结果表明,在苹果中主要存在5 个TMT 家族基因,均含有11 个跨膜区,并具有1 个长约330 氨基酸的亲水loop 区位于胞质内,它们与拟南芥和葡萄的TMTs 高度同源。定量表达分析发现,它们均在苹果中表达,且MdTMT1 表达量相对最高,MdTMT3和MdTMT4 表达量较低。MdTMT1 在花和成熟果实中表达量最高,MdTMT2 在成熟果实中表达最高。在果实发育过程中,MdTMT1 和MdTMT2 的表达量与果实中总糖、还原性总糖、果糖、蔗糖含量呈极显著正相关,说明MdTMT1 和MdTMT2 可能参与了苹果果实成熟期果糖和蔗糖的积累。     

外源NO对干旱胁迫下平邑甜茶幼苗叶绿素荧光参数和光合速率的影响

 以20%聚乙二醇（PEG6000）处理模拟干旱,利用一氧化氮（nitric oxide,NO）供体硝普钠（sodium nitroprusside,SNP）处理平邑甜茶[Malus hupehensis（Pamp.）Rehd.]幼苗,探讨外源NO对水分胁迫下平邑甜茶幼苗叶绿素荧光参数和光合速率的影响。结果表明：水分胁迫下平邑甜茶幼苗Fo显著上升,F_v/F_m、q_P、ETR、Yield、叶绿素含量和光合速率显著降低,q_N在胁迫的前3 d呈上升趋势,之后大幅度下降;通过外施不同浓度的SNP（100 ~ 700 μmol · L^-1）均使水分胁迫下平邑甜茶幼苗 F_o上升及F_v/F_m、ETR、q _P、Yield、叶绿素含量和光合速率下降幅度明显减小。不同处理缓解作用为：300 μmol · L^-1 SNP > 500 μmol · L^-1 SNP > 100 μmol · L^-1 SNP > 700 μmol · L^-1 SNP,其中300 ~ 500 μmol · L^-1 SNP处理缓解效应明显,但以300 μmol · L^-1 SNP处理效果最好。     

氮胁迫对平邑甜茶水培苗的生理效应

以当年生平邑甜茶(MalushupehensisRehd.)实生苗为试材,用水培实验方法,研究氮胁迫对其引起的生理效应。通过8周的处理,对平邑甜茶的功能叶和根系进行相关指标的检测,结果如下:用电导仪进行抗逆性测定,伤害率由大到小依次为功能叶、吸收根、生长根和木质根。N胁迫影响了功能叶和根系中的N代谢。与MN(middleN)相比,N胁迫各处理的可溶性蛋白含量均下降。功能叶中游离氨基酸总量表现为HN(highN)>LN(lowN)>MN,而根系中表现为MN>HN>LN。各器官中,以功能叶和吸收根对N胁迫最为敏感。N胁迫还改变了功能叶和吸收根内的ABA、IAA、ZRs、GA3的含量,从而影响了激素平衡。此外,通过电镜观察可知,N胁迫破坏了叶绿体和吸收根根尖细胞的超微结构。     

Heat treatment and harvest date interact in their effect on superficial scald of ‘Granny Smith’ apple

A study was made of the effect of hot water dips (HWD) at temperatures of 42, 44, 46 and 48 °C (HWD 42 °C, HWD 44 °C, HWD 46 °C and HWD 48 °C, respectively) for 3 min on development of superficial scald and the concentration of α-farnesene and conjugated trienols (CT), CT₂₅₉, CT₂₆₉, CT₂₈₁, as well as OD₂₀₀ on Granny Smith apple fruits harvested on three dates and stored 125 days in air at 2 °C. HWD 48 °C efficiently decreased surface scald in the second and third harvest. α-Farnesene and CT were measured spectrophotometrically and by HPLC. No clear relationship of OD₂₀₀ and scald development was observed. Correlation of scald index and OD₂₀₀ at the end of storage was negative for the second harvest date. There was no significant correlation between the scald index and CT₂₅₉. Scald index was positively correlated with CT₂₆₉ after 80 days for the second and third harvest and at the end of storage for the second harvest. CT₂₈₁ was spectrophotometrically detectable only at the end of the storage, for the third harvest date, in control, HWD 42 °C, and HWD 44 °C. HWD 42 °C had significantly higher CT₂₈₁ compared to HWD 44 °C and control. HPLC analysis of control samples revealed presence of CT₂₈₁ in all three harvest dates, and presence of at least two components, as was the case of CT₂₅₉ and CT₂₆₉. The ratio of these two components was different for all three CT species. Fruit maturity was an important factor determining the response of fruit to heat and occurrence of superficial scald. The results indicate that a successful treatment using HWD to control superficial scald may be obtained after further research and that there are still some questions on the role of different CT's in scald biochemistry that should be addressed in future research.     

Rootstock effect on growth of apple scions with different growth habits

Apple scions with diverse growth habits were grafted on various size-controlling rootstocks and morphological characteristics were measured after 6 years of growth in the field. Scion had more influence than rootstock on monthly growth rate. Across all rootstocks, scions with spreading growth habits grew rapidly in April and May and achieved most seasonal growth earlier than scions with upright growth habits that grew slowly early in the season. In all growth habits and rootstocks, growth rate slowed appreciably but did not cease by August and growth did not terminate earlier for any one scion–rootstock combination. Across all scions, the dwarfing rootstock, M.9, consistently had the lowest and seedling rootstock had the greatest tree height and trunk diameter. However, no one size-controlling rootstock consistently influenced dates of bud break and full bloom, shoot elongation rate, or duration of growth. Tree growth form was not fundamentally affected by rootstock. Significant interactions indicated that effects of size-controlling rootstock on components of shoot growth will vary with apple tree growth habit. These effects on phenology and development can be significant to growers and may assist breeders in developing new apple cultivars.     

Effects of root inoculation of plant growth promoting rhizobacteria (PGPR) on yield,growth and nutrient element contents of leaves of apple

From 2002 to 2006, plant growth promoting effects of Bacillus M3, Bacillus OSU-142 and Microbacterium FS01 were tested alone or in combination on apple (Malus domestica L.) cv. Granny Smith in terms of yield, growth and nutrient composition of leaves in the province of Malatya, Turkey. The presence of M3 and/or OSU-142 and/or FS01 combinations stimulated plant growth and resulted in significant yield increases in Granny Smith. Root inoculation of PGPR strains significantly increased cumulative yield (26.0–88.0%), fruit weight (13.9–25.5%), shoot length (16.4–29.6%) and shoot diameter (15.9–18.4%) compared with the control. In addition, all nutrient element contents (N, P, K, Mg, Ca, Fe, Mn and Zn) investigated in Granny Smith, except Mg was significantly affected by bacterial applications compared with the control. The highest N content (3.38%) was obtained from OSU-142 + FS01 application. Phosphorus contents of leaves of Granny Smith increased from 0.29% in the control to 0.42, 0.37, 0.36, 0.36 and 0.35% by M3, M3 + FS01, M3 + OSU-142, OSU-142 and M3 + OSU-142 + FS01 application, respectively. All bacterial applications significantly increased Ca content of leaves. The highest K, Fe, Mn, Cu and Zn content of leaves were obtained from OSU-142, M3, FS01, M3 and M3 + FS01 applications, respectively. The results of this study suggest that Bacillus M3 and/or OSU-142 and/or Microbacterium FS01 in combination have the potential to increase the yield, growth and nutrition of apple trees.