梁王山大花香水月季居群表型多样性分析

以云南省澄江市梁王山一带3个大花香水月季居群240个个体为研究对象,采用巢式方差分析、表型变异系数分析、Pearson相关性分析等方法,对大花香水月季的花、叶等16个表型性状进行分析。结果表明:大花香水月季居群内和居群间均存在丰富的表型多样性,表型分化系数在-1.51%～26.18%之间,在较近的距离内,居群内多样性远高于居群间多样性。表型性状在居群内的平均变异系数为13.62%,离散程度相对较低,其中,变异系数最大的是花梗长,最小的是花瓣长宽比。相关性分析发现,大多数花部性状间、叶部性状间相关性较强,但花部性状与叶部性状之间相关性较低甚至不相关。     

气候变化背景下基于MaxEnt模型的刺梨潜在适生区分布预测

为阐明气候变化背景下刺梨(Rosa roxburghii)在中国的潜在适生区分布,该研究基于刺梨的自然分布数据及当代(1960~1990)、未来(21世纪50年代及70年代)气候因子数据,采用最大熵(MaxEnt)模型模拟了当前和未来气候情景下刺梨在中国的潜在适生区,并确定影响其地理分布的主要气候因子。结果表明:(1)温度因子是影响刺梨分布的关键气候因子,尤其是最冷月份最低温度(BIO06)对模型的百分比贡献率和排列重要性分别为66.7%和53.4%。(2)在当代气候条件下,刺梨的总适生区面积为3.50×10⁶km²,占中国陆地面积的36.44%。其中,高度适生区面积为2.05×10⁵km²,占总适生区面积的5.87%,主要分布在贵州西部、四川中部及川渝陕边境。(3)未来气候变化情景下,刺梨的总适生区和低度适生区面积将增加,而中、高度适生区面积将减小。在21世纪70年代RCP4.5气体条件下,中、高度适生区面积均出现最小值,分别为7.07×10⁵km²和2.80×10⁴km²,仅占当代中、高度适生区面积的53.30%和13.65%。研究发现,刺梨的适生区随着气候变化略增加并有向高纬度地区迁移的趋势,但在四川中部及川渝陕边境的高度适生区显著减少,将来主要分布于贵州省。     

月季花瓣数量遗传分析

以‘窄叶藤本月季花’(Rosa chinensis‘Zhaiye Tengben Yuejihua’)ב月月粉’(R.chinensis‘Old Blush’)杂交群体为材料,分析其花瓣数量的分离特点,对单瓣花与重瓣花的花芽分化过程进行观察,并对花瓣、雄蕊及瓣化雄蕊进行表皮细胞超微结构的观察。结果显示:杂交群体的花瓣数量分离明显,出现从5~54片的连续变异;花瓣数量、瓣化雄蕊数量、雌蕊数量的遗传模型为2MG-AD(2对加性-显性-上位性主基因控制),雄蕊数量的遗传模型为0MG(无主基因控制);月季重瓣花形成的原因为雄蕊瓣化,重瓣花形成的关键时期为雄蕊原基形成后期,可见到雄蕊瓣化为花瓣的现象;月季瓣化雄蕊的表皮细胞形态、褶皱程度介于单瓣花花瓣和重瓣花外轮花瓣之间。     

Blue light effects on rose photosynthesis and photomorphogenesis

Through its impact on photosynthesis and morphogenesis, light is the environmental factor that most affects plant architecture. Using light rather than chemicals to manage plant architecture could reduce the impact on the environment. However, the understanding of how light modulates plant architecture is still poor and further research is needed. To address this question, we examined the development of two rose cultivars, Rosa hybrida‘Radrazz’ and Rosa chinensis‘Old Blush’, cultivated under two light qualities. Plants were grown from one‐node cuttings for 6 weeks under white or blue light at equal photosynthetic efficiencies. While plant development was totally inhibited in darkness, blue light could sustain full development from bud burst until flowering. Blue light reduced the net CO₂ assimilation rate of fully expanded leaves in both cultivars, despite increasing stomatal conductance and intercellular CO₂ concentrations. In ‘Radrazz’, the reduction in CO₂ assimilation under blue light was related to a decrease in photosynthetic pigment content, while in both cultivars, the chl a/b ratio increased. Surprisingly, blue light could induce the same organogenetic activity of the shoot apical meristem, growth of the metamers and flower development as white light. The normal development of rose plants under blue light reveals the strong adaptive properties of rose plants to their light environment. It also indicates that photomorphogenetic processes can all be triggered by blue wavelengths and that despite a lower assimilation rate, blue light can provide sufficient energy via photosynthesis to sustain normal growth and development in roses.     

新疆东天山地区宽刺蔷薇居群表型多样性分析

对新疆东天山地区6个宽刺蔷薇（Rosa platyacantha）居群进行叶片、花序、果实、种子等11个表型性状的遗传多样性分析,结果表明：宽刺蔷薇各表型性状无论在居群间还是在居群内均表现出显著或极显著差异,存在丰富的表型多样性。6个居群11个性状的平均表型分化系数为27.50%,表明居群内多样性较居群间多样性更为丰富。各表型性状平均变异系数为16.51%,离散程度相对较低。对表型性状进行的变异系数多重比较和主成分分析均显示,果实相关性状的变异是造成宽刺蔷薇表型变异的主要来源。性状相关性分析进一步发现,生殖生长与前期的营养生长并无明显相关关系。聚类分析结果表明,6个宽刺蔷薇居群的表型性状并没有严格依地理距离聚类,而是受到遗传因素与环境条件特别是海拔因子的共同影响。     

‘香槟’月季的组织培养和试管开花诱导

本文对‘香槟’月季（80sachinensis‘Xiangbin’）的组织培养技术和诱导试管开花进行了研究。结果表明：以茎段为外植体能诱导获得无菌苗,适宜的启动培养基为MS＋6-BA1．0mg-L-1＋IBA0．1mg·L-1,幼芽继代增殖的最佳培养基是MS＋6．BA1．0mg·L-1。＋IBA0．1～0．2mg·L-1,诱导生根的适宜培养基为1／2MS＋NAA0．3mg·L-1,生根率达80．0％。诱导试管开花的适宜培养基为MS＋6．BA0．5mg·L-1＋NAA0．1mg·L-1最适宜的诱导试管开花的蔗糖含量是30g·L-1;在三角瓶中培养,试管花可以正常开放,在培养瓶中培养花芽不能正常开放;MS培养基中增加2倍磷的含量,可以提高花芽诱导率,为25．O％;诱导试管开花的最适培养条件为温度21℃,光照强度80～100μmol·m-2．s-1,光照时间16h—d-1。     

Rapid Purification and Crystallization of Thermostable Malate Dehydrogenase Isolated from a Thermophilic Bacterium,Thermus flavus AT 62

A structural study of the water-soluble dextran made by Leuconostoc mesenteroides strain C (NRRL B-1298) was conducted by enzymic degradation and subsequent ¹³C-NMR analysis of the native dextran and its limit dextrins. The α-l,2-debranching enzyme removed almost all of the branched D-glucose residues, and gave a limit dextrin having a much longer sequence of the internal chain length (degree of linearity: n = 24.5 compared with the value of n = 3.3 for the native dextran). The degree of hydrolysis with debranching enzyme corresponded to the content of α-1,2-linkages determined by chemical methods, which suggested that most of the α-l,2-linkages in the dextran B-1298 constituted branch points of a single D-glucose residue. A synergistic increase of susceptibility of the dextran B-1299 was observed by simultaneous use of debranching enzyme and endodex-tranase. ¹³C-NMR spectral analysis indicated the similarity of structure of dextran B-1298 to that of B-1396, rather than that of B-1299. Occurrence of α-l,3-linkages in the limit dextrin was supported by a newly visualized chemical shift at 83.7 ppm.     

Population Dynamics and Damage Potential of Meloidogyne hapla to Rose Rootstock Species

The relationship between initial population densities (Pi) of Meloidogyne hapla on growth of three rose rootstocks (Rosa corymbifera ‘Laxa’, R. multiflora and R. canina ‘Inermis’) and nematode population development was studied. Each plant species was inoculated with ranges of nematode densities of 0, 0.062, 0.125, 0.25, 0.50, 1, 2, 4, 8, 16, 32, 64 and 128 second‐stage juvenile/g soil and were allowed to grow for 9 weeks. Seinhorst yield model was fitted to total fresh biomass data of the rootstocks. The tolerance limits (T) were 0.04, 0.09 and 0.01 J2/g soil and the minimum yield (m) 0.65, 0.47 and 0.43 for R. corymbifera ‘Laxa’, R. multiflora and R. canina ‘Inermis’, respectively. The reproductive factor (Pf/Pi) was highest at low initial nematode densities for all rootstocks and then decreased to below maintenance level with increasing initial population densities. Root gall severity consistently increased with initial nematode population density. Furthermore, number of root galling showed a strong positive relationship with final nematode population per gram root fresh weight. The relation between Pi and Pf was also fitted to the Seinhorst population model (Pf = (M*Pi)/Pi + M/a). Rosa multiflora supported the population of M. hapla to a maximum population density (M) of 27.53 J2/g soil with an estimated average maximum multiplication rate (a) of 24.39. For R. corymbifera ‘Laxa’ and R. canina, the maximum multiplication rate was 4.34 and 3.62 and the maximum population density 6.08 and 4.78 J2/g dry soil, respectively. Hence, it was demonstrated that all three rootstocks were susceptible to even low initial nematode densities and therefore are considered good hosts for M. hapla.     

月季F1代群体表型性状变异分析

以月季（Rosa spp.）品种‘云蒸霞蔚’和‘太阳城’正交获得的184株F₁代群体为研究对象,采用方差分析、变异系数、遗传分析、相关性分析对花部形态性状以及叶片形态性状进行测定分析。结果表明：该杂交群体表型变异丰富,变异系数在7.33%~68.08%,其中花瓣数量在群体中的变异程度最高;杂交后代各个性状上均发生分离变异,出现不同于亲本的表现型,且离散程度较高。表型性状的遗传特点与关联分析,为挖掘控制表型性状的优良基因及辅助选择育种提供参考。