45份青海春小麦品种矮秆基因检测及效应分析

为明确矮秆基因Rht-B1和Rht-D1在青海春麦区小麦品种中的分布，以青海春麦区历年种植的45份春小麦品种（25份育成品种，14份引进品种，6份地方品种）为材料，利用KASP标记技术检测其两个矮秆基因的分布，并分析这两个矮秆基因对株高、穗长、小穗数和穗粒数的影响。结果表明，Rht-B1位点上存在Rht-B1a和Rht-B1b两种等位变异，分布频率分别为91.11%和8.89%；Rht-D1位点上存在Rht-D1a和Rht-D1b两种等位变异，分布频率分别为86.67%和13.33%。25份育成品种中，Rht-B1b和Rht-D1b的分布频率分别为16.00%和12.00%，未发现Rht-B1a和Rht-D1a；引进品种中仅含有Rht-D1b，分布频率为21.43%；地方品种中未发现Rht-B1b和Rht-D1b。Rht-B1b和Rht-D1b均具有一定的降秆效应，Rht-D1b的降秆效应大于Rht-B1b。携带Rht-B1a/Rht-D1b品种的株高显著低于携带Rht-B1a/Rht-D1a和Rht-B1b/Rht-D1a的品种，该组合类型不仅可使株高降低，也可增加小穗数和穗粒数；未发现携带Rht-B1b/Rht-D1b组合类型的品种。     

甜樱桃不同砧穗组合成花调控关键基因表达差异研究

为了研究甜樱桃(Prunus avium)成花调控关键基因在不同砧穗组合中表达差异,以甜樱桃‘艳阳’(Sunburst)为接穗,‘ZY-1’(P.cerasus)、马哈利(P.mahaleb)和‘兰丁2号’(P.avium × P.pseudocerasus)为砧木的嫁接组合为试材,调查统计4年干龄不同砧穗组合的总花芽量及开花情况;克隆甜樱桃成花调控网络中EARLY FLOWERING 3(ELF3)、CONSTANS(CO)、FLOWERING LOCUS T(FT)等9个关键作用基因,并利用实时荧光定量PCR对不同砧穗组合接穗的幼叶、叶芽、成龄叶、花芽、叶芽附近叶片叶柄及花芽附近叶片叶柄中这些基因的表达量鉴定。结果显示,艳阳/ZY-1、艳阳/马哈利和艳阳/兰丁2号组合的平均单株花芽量分别为279、288和317朵,不存在明显差异,但不同组合的花期却明显不同,当艳阳/马哈利有72%花芽处于开放期时,艳阳/兰丁2号的花开放比例只有7%,艳阳/ZY-1的花开放比例为49%;此外,PaELF3、PaCO、PaFT等9个成花关键基因,在同一时期不同砧穗组合的接穗组织中表达量存在差异,其中PaAP1在不同砧穗组合的花芽中表达模式与花期规律一致,表明PaAP1与樱桃花期调控密切相关。     

拉枝角度对‘SH1’矮化中间砧‘富士’苹果幼树生长和结果的影响

旨在为‘SH1’矮砧‘富士’提供幼树树形管理的科学依据。本研究以4年生‘SH1’矮砧‘富士’为试材,通过70°、90°、120°3种拉枝角度的处理,探讨不同拉枝角度对苹果幼树生长和结果的影响。结果表明:拉枝角度120°时叶片光合速率最大,且与其他2个处理差异显著(P0.05);拉枝角度90°时叶绿素a、叶绿素b和总叶绿素含量最高、叶片厚度、百叶重最大,与其他2个处理差异显著(P0.05);拉枝角度90°时的冠下光合间接辐射最大,拉枝角度120°时株间光合间接辐射、光合直接辐射和叶面积指数均最大;拉枝角度90°时长枝的长度、粗度最大,中枝粗度最大,拉枝角度120°时中枝长度最长;拉枝角度90°时果实单果重、果形指数、可溶性固形物含量、硬度均最大。综合考虑树体生长势和果实品质等因素,90°为‘SH1’矮砧‘富士’枝条适宜的拉枝角度。     

NaCl胁迫对2种柑橘砧木生长及盐离子分布的影响

以耐盐性不同的柑橘砧木枳和枸头橙为材料，分析NaCl胁迫后植株生长表现以及盐离子（Na+和Cl-）在叶片、茎和根中的含量。结果表明：NaCl胁迫降低了植株的株高和干重，而枳的下降幅度高于枸头橙。NaCl胁迫导致2种砧木叶片相对电导率升高，枳高于枸头橙。此外，NaCl处理后2种砧木叶片、茎和根中的Na+和Cl-含量均上升。除了处理21天内枳叶片Cl-含量低于枸头橙外，其他时间枳叶片和茎中的盐离子含量均高于枸头橙。在根中，NaCl处理15天内枳中的Na+和Cl-含量高于枸头橙，其后则是枸头橙高于枳。     

A 192bp allele at the <Emphasis Type="Italic">Xgwm261</Emphasis> locus is not always associated with the <Emphasis Type="Italic">Rht8</Emphasis> dwarfing gene in wheat (<Emphasis Type="Italic">Triticum aestivum</Emphasis> L.)

The height-reducing gene Rht8 was introduced into Italian wheats by breeder Nazareno Strampelli from the Japanese landrace Akakomugi, and has been widely used in wheats adapted to southern and eastern European conditions. Following identification of a close linkage to Rht8, microsatellite marker Gwm261 has been used extensively to screen large numbers of diverse international germplasm. A 192bp allele at this locus has been taken as “diagnostic” for Rht8 and used to infer the international distribution of Rht8. In this paper, we report several instances of cultivars and mapping populations that vary for the presence of the 192bp allele at the Xgwm261 locus (Xgwm261 ₁₉₂ ), but with no associated reduction in height, suggesting a lack of association with Rht8. For instance, in the population derived from a cross between Sunco (Rht-B1b, Xgwm261 ₁₆₅ ) and Tasman (Rht-D1b, Xgwm261 ₁₉₂ ), there were significant height differences associated with the segregation of Rht-B1b and Rht-D1b, but no height differences between Xgwm261 genotypes. Similar results were obtained in a population derived from the cross between Molineux (Rht-B1b, Xgwm261 ₁₉₂ ) and Trident (Rht-D1b Xgwm261 ₂₀₈ ). In contrast, the cross between Trident and Chuanmai 18 (Xgwm261 ₁₉₂ ) gave significant height effects at both the Rht-D1 and Xgwm261 loci, with no epistatic interaction between loci. Chuanmai 18 is closely related to the Strampelli wheat Mara (ancestrally derived from Akakomugi) and is therefore likely to carry Rht8. The old Japanese cultivar Norin 10, used by Norman Borlaug to introduce Rht-B1b and Rht-D1b into Mexican wheats, also has a 192bp allele at the Xgwm261 locus, and the sequence of the amplified product is identical to that of Akakomugi. We suggest that the widespread use of Norin 10-derived germplasm during and after the Green Revolution introduced a second haplotype into international germplasm, in which Xgwm261 ₁₉₂ has no association with Rht8. Therefore, the presence of Xgwm261 ₁₉₂ is only indicative of Rht8 in wheat cultivars that have inherited this allele from Akakomugi or a Strampelli wheat ancestor.     

盐胁迫对甜樱桃“吉塞拉”砧木光合指标的影响

以甜樱桃砧木“吉塞拉6号”(G6)、“吉塞拉5号”(G5)、Y1和B5的1a生盆栽实生苗为试材,探讨了不同浓度NaCl处理对其光合指标的影响.结果表明:盐胁迫影响了“吉塞拉”砧木的光合色素含量、光合参数和叶绿素荧光参数.随着NaCl处理浓度增加和处理时间延长,各试材的净光合速率(Pn)、气孔导度(Gs)和蒸腾速率(Tr)、PSⅡ潜在活性(Fv/Fo)、实际原初光能转化效率(φPSⅡ)和表观电子传递速率(ETR)显著下降,其中B5的下降趋势相对平缓.盐胁迫对“吉塞拉”砧木的效应既有处理间差异,又有品种间差异.轻中度盐胁迫(3‰ NaCl和6‰NaCl处理前中期)并未明显抑制各试材的PSⅡ活性,重度盐胁迫导致各试材PSⅡ受损,光合受到抑制.比较而言,B5的抗盐性优于其它3种试材.     

水分胁迫对扁桃砧木干物质和叶绿素含量的影响

以新疆常用的扁桃砧木石头扁桃和毛桃的1年生实生苗为材料,设置土壤相对含水量分别为田间最大持水量的100%、80%、60%、40%和20%5个处理,研究了不同水分胁迫条件对其干物质和叶绿素含量的影响。水分胁迫处理第10、20、30天后取样,测定其叶绿素含量;在水分胁迫处理第30天取样测定其干物质含量。结果表明:2个供试品种对水分胁迫的反应一致。在土壤相对含水量为80%时,总干物质含量和叶质量比最高,土壤相对含水量较多或较少都会减少干物质的积累,石头扁桃总干物质含量和叶质量比的下降幅度大于毛桃。根质量比和根冠比在土壤相对含水量为80%时最低,随着水分胁迫程度的加剧,根质量比和根冠比升高,石头扁桃的升高幅度大于毛桃。在土壤相对含水量为80%时叶绿素a和叶绿素(a b)的含量最高,随着胁迫程度的加剧和时间的延长,叶绿素a和叶绿素(a b)的含量降低,石头扁桃的降低幅度大于毛桃。     

Scion-rootstock relationships with respect to height growth and foliar concentrations of nitrogen and phosphorus in reciprocal grafts of Pinus caribaea var. hondurensis

Both scion and rootstock clones significantly influenced scion elongation and concentrations of nitrogen and phosphorus in the scion foliage. Scion clone was the more important determinant. Scion clone × rootstock clone interactions were not significant. The ability of a clone to elongate as a scion was not correlated with its capacity to promote or retard scion elongation when used as a rootstock. Genetic differences in foliar nutrient concentrations appeared to reflect levels of nutrient demand, rather than the ability of roots to absorb nutrients. Nutrient demand of the rootstock can also explain negative correlations between nitrogen levels in rootstock clones and levels of both nitrogen and phosphorus in the scions. There was no significant relationship between scion elongation and foliar nitrogen concentrations of either rootstock or scion. The weak relationship between scion elongation and concentration of phosphorus in the rootstock apparently resulted from tissue dilution.     

甜樱桃四倍体杂种砧木Y1高频、高效离体再生体系研究

以甜樱桃四倍体矮化砧木Y1试管苗叶片为外植体,探讨了不同基本培养基、激素组合、暗培养时间和叶片发育阶段对其不定芽再生的影响,建立甜樱桃四倍体矮化砧木的高频、高效离体再生体系,为进一步进行遗传转化研究奠定基础。结果表明,甜樱桃四倍体矮化砧木Y1采用WPM培养基再生效果最好,明显优于MS和DKW培养基;最佳激素组合为6-BA2.0 mg.L-1+IBA1.0 mg.L-1;接种后暗培养可以明显提高不定芽再生率,最适宜暗培养时间为14 d;Y1试管苗顶部完全展开的幼嫩叶片再生能力最高。通过以上条件的优化,成功建立了甜樱桃四倍体矮化砧木的高频、高效离体再生体系,离体叶片不定芽再生率达90%,每叶片平均再生不定芽数达4.1。     

葡萄砧木在贺兰山东麓扦插生根与成苗特性初探

为了加快优良葡萄砧木在贺兰山东麓地区的研究和应用进程,2008～2009年对11个砧木品种进行了硬枝扦插试验,采用目前生产上常用的硬枝扦插技术,研究了在宁夏贺兰山东麓生态条件下,葡萄砧木生根成苗特性的关系,以期为葡萄砧木的选择和大量繁育提供依据,为优良葡萄砧木的大量应用打下一定的基础。