濒危植物缙云卫矛果实、种子形态分化研究

对缙云卫矛7个天然种群的果实、种子形态进行研究,测量果实和种子的数量、长度、宽度、重量等22项形态学指标。结果显示:果实、种子的形态性状在种群内和种群间均存在一定程度的变异,种群间变异系数平均值从0.750(种子数/序)到0.062(种子整体形态,长/宽),相比之下种子整体形态最为稳定。在种群水平上,果实、种子的形态性状有一定程度的分化,但不与种群间的地理距离远近相关联。形态分化与环境因子的灰色关联度分析表明,在所研究的环境因子中,没有发现一单一因子对其形态分化起绝对主导作用,不同环境因子对同一性状所起作用不同,且同一环境因子对不同性状的影响效应也有差异。潜在的主导因子是土壤中的全钾含量、土壤厚度以及土壤pH。     

不同种群中海南粗榧(Cephalotaxus mannii)形态变异研究

通过变异系数和性状差异显著性检验,研究了海南粗榧在坝王岭等５个种群内和种群间不同形态变异以及形态总体变异。结果表明：①海南粗榧营养器官性状比生殖器官性状变异大;枝性状组中,分枝角度变异较小;叶性状组中,叶数量变异较大;球果、种子生物量变异都大于它们的其它性状。②在５个种群内,同一性状变异幅度基本相同。③同一性状在种群间和种群内的变异基本接近。④不同性状在种群间存在差异,有的显著,有的不显著,但种群间形态总体差异都不显著     

天然红松种群形态特征地理变异的研究

在我国红松天然分布区内,根据纬度和海拔的差异,选取了凉水、小北湖和长白山３个地区具有典型代表性下的天然红松林,进行了形态结构的观测分析。分单株采样,测量了一级枝针叶的长度,球果长度、宽度、每球果含种子数目,种子的重量,树皮的形态。结果表明：红松平均针叶长度在我国分布区风呈现中间长、南北短的趋势。种群内针叶的变异幅度凉山地区最大（０．１４８６）,长白山地我最小（０．１０５６）;种群间针叶长度变异较大     

元宝枫天然种群种实表型多样性

为探索元宝枫(Acer truncatum)种群间和种群内的表型变异程度和变异规律,以元宝枫主要分布区内15个天然种群150个单株的13个种实性状为研究材料,采用巢氏方差分析、多重比较等分析方法,分析元宝枫种群间和种群内的表型多样性及其与地理生态因子间的相关性。结果表明:元宝枫果实、种子性状在种群内、种群间存在丰富的变异,各种实性状在种群内、种群间均具有极显著差异;元宝枫种群间表型分化系数为19.87%,种群内变异(80.13%)大于种群间变异(19.87%),种群内变异是变异的主要来源;元宝枫各性状平均变异系数为13.34%,变异幅度为8.98%~21.45%,种群间种子性状的平均变异系数(11.46%)低于种群间翅果性状的平均变异系数(14.52%),表明种子性状的稳定性高于果实性状。主成分分析结果显示,果实形态对元宝枫种群表型的贡献率大于种子贡献率。性状间相关性分析结果显示,翅果越大则种子越大,果翅角度性状与果实、种子大小皆无显著关系,推测其为独立因子。果实形态变异主要表现为经向变异,而种子性状无显著变异。利用种群间聚类分析将元宝枫15个种群分为三大类群。种群间与种群内多层次的变异模式为元宝枫种质资源保护与利用提供依据。     

珍稀油料树种琴叶风吹楠果实和种子形态变异

以云南野生琴叶风吹楠(Horsfieldia pandurifolia)为材料,对39株树的果实和种子的形态进行变异分析。结果表明,果实和种子形态指标株间变异大,株内变异小。单株间果实表现出从卵圆形至长椭圆形的变异,果长4~7 cm,先端圆钝至锐尖,基部不同程度偏斜,与文献记录差异较大;单株间种子形态表现出从卵形、长卵形至细长形或近锥形的变异。单株平均种长变幅为25.05~35.66 mm,种宽为13.30~19.62 mm,长宽比为1.47~2.32,单因素方差分析表明此3个性状单株间差异极显著(p<0.01)。灰白色种皮具褐色斑块,种脐和胚位于种子基部,种子先端突尖或具短喙是稳定的性状,有重要的分类学价值。     

中国东部亚热带青冈果实形态变异的研究

青冈为我国亚热带地我广泛分布,并具有较强耐寒和耐瘠薄能力的少数几个常绿树种之一,以果实长度,宽度和体积作为果实大小的指标,宽／长作为果实形状的指标,对采自东部亚热带的１０个青冈和群果实形态进行了比较分析,结果如下：（１）青冈果实的大小和形状在种群间,种群内均存在着显著差异,变异幅度最大的是果实的体积（种群间的变异幅度ＣＶ１为５７．１％,种群间平均单粒果实体积的最大差异为３．５倍）其次为宽度（２１．     

药物植物桃儿七不同种群种子产量初步研究

对药用植物桃儿七5个不同种群种子产量的研究表明：各种群中每花平均胚珠数、每果实平均种子数及种群平均结实率与种群所在的海拔高度呈正相关;不同种群个体平均胚珠数的变异范围为58.97-87.97,平均种子数变异范围为40.02-80.58,平均结籽率变异范围为61.29%-91.60%;果料内单粒种子平均干重与种群分布海拔呈明显负相关,与果实内种子数呈弱负相关;同一种群在不同年份间平均各上子产量差异不大;种子产量除主要受个体营养状况影响外,还受海拔及其它因素的影响;果实内种子数与果实大小及重量呈正相关,但单粒种子平均重量与果实大小及果实内种子总重量无显著相关。     

甘草野生种群果实与种子形态特征的地理变异研究

目的:研究甘草荚果和种子形态特征地理变异规律并分析其形成的生态学机制。方法:采用样方调查的方法测定全国4省区8个旗县甘草野生种群的地上植株形态特征,采用双重筛选逐步回归分析方法探讨甘草荚果和种子形态特征的地理变异规律及其形成的生态学机制。结果:(1)不同甘草种群的荚果数、荚果腺毛长度、种室数目、每荚种子粒数和结实率5项指标的差异达到了极显著水平(P<0.01);荚果长度、荚果厚度、荚果腺毛密度和种子长度4项指标的差异达到了显著水平(P<0.05)。(2)荚果厚度、种室数目等5项形态特征与经度呈显著相关,只有荚果腺毛长度1项指标与纬度显著相关。结论:甘草野生种群荚果与种子形态特征存在显著的地理变异,其变异趋势以经向变异为主,光照因子差异是导致地理变异的主要原因,其次为温度因子和水分因子,其相关关系可用多元回归模型解释。     

蒙古沙拐枣种群形态和同工酶变异的比较研究

调查和测定了中国西北荒漠地区的蒙古沙拐枣(Calligomum mongolicum Turcz)5个种群的形态学指标,应用方差分析(MANOVA)、主成分分析(PCA)和聚类分析,对种群间及种群内的形态性状进行研究。结果表明,种群间的形态变异差异显著。植株高度、种子刺毛长度和种子重量指标具有较强的形态差异性分析意义。形态差异(欧氏距离)与种群间基因流动(地理距离)间没有发现相关关系。聚类分析结果表明,种群M1与M2亲缘关系最近,种群M5与其他种群的亲缘关系相对较远;采用垂直板聚丙烯酰胺电泳技术对5个种群的3个酶系统进行了遗传多样性分析,结果表明,种群M5与其他种群的遗传一致度稍低(0．8197～0．8902)以外,其余各种群遗传一致度较高(0．8480～0．9505),体现其亲缘关系较近。依据Nei的遗传距离进行聚类,结果与形态聚类结果有一定的相似性。     

甘草野生种群果实与种子形态特征的地理变异研究

目的：研究甘草荚果和种子形态特征地理变异规律并分析其形成的生态学机制。方法：采用样方调查的方法测定全国4省区8个旗县甘草野生种群的地上植株形态特征,采用双重筛选逐步回归分析方法探讨甘草荚果和种子形态特征的地理变异规律及其形成的生态学机制。结果：（1）不同甘草种群的荚果数、荚果腺毛长度、种室数目、每荚种子粒数和结实率5项指标的差异达到了极显著水平（P〈0．01）;荚果长度、荚果厚度、荚果腺毛密度和种子长度4项指标的差异达到了显著水平（P〈0．05）。（2）荚果厚度、种室数目等5项形态特征与经度呈显著相关,只有荚果腺毛长度1项指标与纬度显著相关。结论：甘草野生种群荚果与种子形态特征存在显著的地理变异,其变异趋势以经向变异为主,光照因子差异是导致地理变异的主要原因,其次为温度因子和水分因子,其相关关系可用多元回归模型解释。     

温度和土壤含水量对青冈栎种子萌发的影响

运用直播法,研究应用人工气候箱控制温度和土壤含水量对野生青冈栎种子萌发和幼苗生长的影响。结果表明:在12h光照条件下,青冈栎种子在变温为10℃/15℃时,萌发率很低,仅为(12±12.29)%;变温为30℃/35℃时,萌发率达最大,为(81±13.7)%。土壤含水量为30%～40%时,萌发率为(79±15.9)%;土壤含水量为90%～100%时,萌发率为(56.67±19.36)%。青冈栎种子萌发呈现出迅速萌发和推迟萌发的特点;温度对青冈栎幼苗的苗高、叶长和叶宽影响显著,对幼苗的地径、叶片数量影响不显著。恒温下,不同梯度土壤含水量处理对幼苗的苗高、地径、叶长、宽影响不显著。     

基于年轮分析的桂林岩溶区青冈栎地上生物量研究

采用年轮分析法对岩溶区青冈栎样树年轮和生物量进行测定并对其群落生物量进行估算。研究结果显示,青冈栎平均树龄46a,平均胸径20.52cm,单位地上生物量为98.668t.hm-2。随着植株的生长,胸径越大则生物量越大,两者形成明显的幂函数关系。d、e、f、g和h样树地上生物量为2.884、22.567、108.183、134.314和379.799kg,生物量分配状况是主干>枝条>树叶,大部分的生物量分配在主干,生物量随着胸径的增大明显加大。     

青藏高原东缘常见40种禾本科植物种子大小变异研究

采集青藏高原东缘常见禾本科植物的种子,测量并计算种子的长、宽、高、质量等9项形态学指标,将上述指标分别与海拔高度、种子质量和种子总体方差间进行相关性分析。结果表明：①种子的各表型性状均存在一定程度的变异,其中种子长/高的变异系数最高,而种子质量的变异系数最低,表明种子质量较稳定。②相关性分析表明种子的长与种子质量间有较强的相关性;海拔高度与禾本科种子表型性状之间存在一定程度的相关性,沿海拔梯度,种子长、种子宽、种子高、种子宽/种子长和种子质量逐步减小;总体方差与种子长/种子高具有较高的相关性。认为可以用种子长/高替代总体方差来衡量禾本科种子的整体形态;海拔是影响禾本科种子大小及变异的一个重要因素。     

Size and crown shape predict reproductive maturity of Carapa guianensis in upland and floodplain forests in the northeastern Amazon

Comprehending the size distribution within a population and grasping its connection to tree maturation (onset of reproductive phase) is pivotal for formulating sustainable management strategies and conserving numerous tree species. The objective of this study was to compare the structure and probability of fruit production of Carapa guianensis in two types of forest (varzea, or floodplain, vs. terra firme, or upland) in the northeastern Amazon, Brazil. The study was conducted in four permanent plots of 300 × 300 m (two for each type of forest). All individuals ≥10 cm in diameter at breast height (DBH) were mapped and measured for DBH, height, and canopy characteristics (shape and position), and liana infestation. Sixty-seven trees were inventoried in the upland forest and 297 in the floodplain forest. The trees were larger in the upland (33.36 ± 1.84 cm) than in the floodplain (21.92 ± 1.5 cm) and more than half (56%) of the upland trees and more than two thirds (67%) of floodplain trees were reproductive. The minimum diameter for fruit production in the floodplain (10.2 cm of DBH) was more than two times smaller than in the upland (25.5 cm of DBH). The probability of fruit production of a tree of the same size was twice as high in the floodplain compared with the upland, and trees with rounded canopies had a higher probability of fruit production in the upland. Our results showed that the probability of fruit production can be modeled with variables of tree size and canopy shape, and that intrinsic factors of the forests influence the reproductive maturity of C. guianensis which presents greater precocity and productive potential of seeds in the estuarine floodplain forest of the Amazon River.     

Quantitative trait loci analysis of morphological traits in Citrus

The objectives of this study were to understand the genetic basis of morphological variation observed in the genus Citrus and its relatives and to identify genomic regions associated with certain morphological traits using genetic linkage mapping and quantitative trait loci (QTLs) analysis with random amplified polymorphic DNA (RAPD) markers. First, a genetic linkage map was constructed with RAPD markers obtained by screening 98 progeny plants from a {Citrus grandis × [C. paradisi × Poncirus trifoliata]} × {[(C. paradisi × P. trifoliata) × C. reticulata] × [(C. paradisi × Poncirus trifoliata) × C. sinensis]} intergeneric cross. The map contains 69 RAPD markers distributed into nine linkage groups. Then, 17 different morphological traits, including six tree and two leaf characters of 98 progeny plants and six floral and three fruit characters of about half of the same progeny plants were evaluated for 2 years and statistically analyzed for variation. Statistical analysis of individual traits indicated that trunk diameter and growth, tree height, canopy width, tree vigor and growth, leaf length and width, petal and anther numbers, petal length and width, length of pistil and style, fruit length and diameter, and fruit segment number showed normal or close to normal distribution, suggesting that these traits may be inherited quantitatively. Quantitative data from the morphological traits were analyzed to detect markers and putative QTLs associated with these traits using interval mapping method. QTL analysis revealed 18 putative QTLs of LOD > 3.0 associated with 13 of the morphological traits analyzed. The putative QTLs were distributed in several different linkage groups, and QTLs associated with similar traits were mostly mapped to the same LG or similar locations in the linkage group, indicating that the same genomic region is involved in the inheritance of some of the morphological traits.     

青藏高原紫穗槐主要形态特征变异分析

应用数量统计方法,对在西藏拉萨市、曲水县和甘肃玛曲县等青藏高原区首次种植的紫穗槐3个居群的17项形态特征指标进行比较分析。变异系数分析结果表明:不同居群内及居群间的形态特征存在一定程度的变异。采用主成分分析方法,找到了积累贡献率达86.603%的4个主成分,新枝长、新枝直径、老枝直径、主根直径、二级侧根总长5个性状是造成紫穗槐形态变异的主要因素,并分析了其与根际土壤生境的相关性。通过对紫穗槐一级侧根与二级侧根根长频率分布研究,表明:(1)不同居群内及居群间各个阶段根长存在差异;(2)居群3(玛曲)中一级侧根和二级侧根根长≥40 cm的频率明显高于另外两个居群。     

Variability in fruit and seed morphology among and within populations of Plathymenia (Leguminosae-Mimosoideae) in areas of the Cerrado, the Atlantic forest, and transitional sites

Plathymenia reticulata is a tree species that occurs in two different Brazilian biomes, the Cerrado (a savannah environment), and the Atlantic Forest. In the present study, we evaluated morphological variation within and among five populations located in these vegetation types and in transitional sites in order to test the hypothesis that habitat selective pressures, being different in the Cerrado and the Atlantic Forest, would cause adaptive differences in morphological traits in individuals occurring under these different circumstances. Thirteen morphological traits of fruits, seeds, and of the membranous endocarp were obtained from 30 fruits and 20 seeds from each of nine to 10 individuals per population. Significant variation was found for all traits while comparing individuals within populations, and most traits varied significantly among populations as well. Some traits differed significantly between forest and Cerrado populations, while transition sites showed intermediate patterns and higher within-population variation. Contrary to our hypothesis, variation in seed size and mass among populations from different habitats was not significant. However, as predicted, the membranous endocarp was shorter for the seeds from Cerrado populations than from the Atlantic Forest. These data suggest the existence of P. reticulata ecotypes from Cerrado and Atlantic Forest; the relevance to Plathymenia evolution and to its wide ecological distribution is discussed.     

Comparative oocyte morphology and fecundity of five characid species from São Francisco River basin,Brazil

The morphology of vitellogenic oocytes and the batch fecundity of five tropical forage species belonging to the family Characidae, were studied in 104 late‐maturing ovaries. Significant morphological differences between vitellogenic oocytes and ovarian follicles were found. The lowest batch fecundity values were recorded in Hemigrammus marginatus (480 ± 163) and Orthospinus franciscensis (1701 ± 562), which were the smaller species in terms of total length, body weight and oocyte diameter. The highest batch fecundity value was observed in Tetragonopterus chalceus (8384 ± 3944) having the highest GSI and oocyte diameter. Batch fecundity and gonad weight was highly correlated followed by body weight and total length. Relative fecundity was estimated per unit total length, body weight and gonad weight. The wide variation in fecundity observed between the specimens and the species analysed is possibly related to the multiple spawning reproductive strategy of these fishes. Since T. chalceus have higher values of batch and relative fecundity, it is concluded that this species has a higher reproductive potential than the other forage species studied.     

短枝木麻黄种群苗期表型多样性评价

以来源于大洋洲原生种源区、亚洲原生种源区、亚洲引种次生区以及非洲引种次生区4个区域的20个种源短枝木麻黄种子和当年生幼苗为材料,通过种子千粒重以及幼苗苗高、地径、一级侧枝粗度、一级侧枝长度等7个性状对短枝木麻黄表型多样性进行了研究,以探讨种群苗期表型遗传差异,为短枝木麻黄早期遗传选择和遗传改良提供基本资料。结果表明:(1)短枝木麻黄种子千粒重在区域间和区域内种源间差异极显著,且千粒重具有显著的地理变异模式,随经度的增大而降低。(2)当年生幼苗苗高、地径在不同区域间及区域内种源间均存在极显著差异,其中泰国干东港种源幼苗生长最好(苗高76.6cm,地径4.64mm),而种源汤加的幼苗生长最差(苗高28.3cm,地径2.58mm)。(3)当年生幼苗一级侧枝粗度、一级侧枝长度、二级侧枝长度、每小枝节数和齿叶数在不同区域间及区域内种源间均存在极显著差异,其中齿叶数在区域间的变异系数最大(82.15%)。(4)通径分析表明,一级侧枝长度对苗高具有显著的正向影响作用,而一级侧枝粗度和二级侧枝长度对地径具有显著正向影响作用,它们可作为短枝木麻黄优良新品种筛选的参考因子。