短日照对于洋麻叶形态变化的影响

洋麻(Hibiscus cannabinus)一生中叶形态的变化有着一定的规律性(雅库希金1947)。茎上基部的叶子为锯齿卵形,中部为深裂叶,叶子的分裂程度随着叶子的层次逐渐加大,菜片由3裂、5裂、发展到7裂。以后分裂的程度开始下降由7裂降到5裂、3裂。顶端的叶子篇锯齿狭长叶。根据以上的现象,可以看出随着洋麻发育的进程叶片分裂的程度有着周期性的变化。洋麻可以用缩短光照的处理来加速它的开花结实。在短光照条件下的洋麻是否因为光照期的缩短加速了叶形态周期性的变化?当洋麻从短光照的条件下进入长光照之     

Quantitative trait locus analysis of leaf dissection in tomato using Lycopersicon pennellii segmental introgression lines

Leaves are one of the most conspicuous and important organs of all seed plants. A fundamental source of morphological diversity in leaves is the degree to which the leaf is dissected by lobes and leaflets. We used publicly available segmental introgression lines to describe the quantitative trait loci (QTL) controlling the difference in leaf dissection seen between two tomato species, Lycopersicon esculentum and L. pennellii. We define eight morphological characteristics that comprise the mature tomato leaf and describe loci that affect each of these characters. We found 30 QTL that contribute one or more of these characters. Of these 30 QTL, 22 primarily affect leaf dissection and 8 primarily affect leaf size. On the basis of which characters are affected, four classes of loci emerge that affect leaf dissection. The majority of the QTL produce phenotypes intermediate to the two parent lines, while 5 QTL result in transgression with drastically increased dissection relative to both parent lines.     

植物叶缘形态的发育调控机理

生物多样性研究的关键问题之一是表型多样性的形成和演化机制, 因为表型多样性与物种多样性密切相关, 同时又承载着遗传和环境的变异信息。植物的叶具有丰富的形态多样性, 而叶形多样性很大程度上体现在叶边缘形态的变异。叶边缘的形态可从全缘、锯齿状到具有不同程度(深浅)和不同式样(羽状或掌状、回数等)的裂片(在发育研究中复叶的小叶也描述为裂片)。关于叶缘齿/裂的发育调控机制, 在拟南芥(Arabidopsis thaliana)、碎米荠(Cardamine hirsuta)、番茄(Solanum lycopersicum)等模式植物中已有较深入的探讨。研究发现, 很多转录因子、小分子RNA及植物激素对叶齿/裂或小叶的形成具有调控作用, 其中生长素输出途径中的转录因子NAM/CUC、miR164以及高浓度生长素的反馈调控可能起到核心作用, 而且该调控模块在真双子叶植物中较为保守; TCP类、SPL类转录因子和其他一些miRNA也在生长素输出途径中发挥作用; 关于KNOX家族转录因子的作用, 虽然多数研究是围绕复叶的形态建成, 但也有数据显示其在叶裂发育中发挥作用。此外, 对拟南芥和碎米荠等十字花科植物的研究还发现, 调控基因RCO通过抑制小叶/裂片之间的细胞增殖而对小叶/叶裂的发育发挥作用。本文综述上述多角度的研究进展, 并尝试概括叶边缘形态的发育调控网络, 为关于叶缘形态多样性形成机制的研究提供可参考的切入点。     

白菜叶裂数性状主基因+多基因遗传分析

以叶片全缘的大白菜自交系(P1)和叶缘深裂的欧洲白菜型油菜自交系(P2)杂交所获得的6个基本世代(P1、P2、F1、B1、B2、F2)为材料,应用主基因+多基因混合遗传模型对白菜叶裂数进行遗传分析。结果表明,白菜的叶裂数受2对加性-显性-上位性主基因+加性-显性多基因的控制,第1对主基因加性效应为-1.154 7,显性效应为-1.516 8;第2对主基因的加性效应为-1.154 8,显性效应为1.034 9;多基因加性效应为0.591 9,显性效应为1.145 2,2对主基因间存在明显的交互作用。B1、B2和F2世代叶裂数的主基因遗传率分别为88.48%、90.40%、93.03%;多基因遗传率分别为4.114%、0、0。B1、B2、F2世代叶裂数表现出较高的主基因遗传率,受环境影响较小。在白菜叶裂数性状的改良中应以主基因为主,并适于早代选择。     

Morphological Variation in Leaf Dissection of Rheum palmatum Complex (Polygonaceae)

Aims

Rheum palmatum complex comprises all taxa within section Palmata in the genus Rheum, including R. officinale, R. palmatum, R. tanguticum, R. tanguticum var. liupanshanense and R. laciniatum. The identification of the taxa in section Palmata is based primarily on the degree of leaf blade dissection and the shape of the lobes; however, difficulties in species identification may arise from their significant variation. The aim of this study is to analyze the patterns of variation in leaf blade characteristics within and among populations through population-based sampling covering the entire distribution range of R. palmatum complex.

Methods

Samples were taken from 2340 leaves from 780 individuals and 44 populations representing the four species, and the degree of leaf blade dissection and the shape of the lobe were measured to yield a set of quantitative data. Furthermore, those data were statistically analyzed.

Important Findings

The statistical analysis showed that the degree of leaf blade dissection is continuous from lobed to parted, and the shape of the lobe is also continuous from broadly triangular to lanceolate both within and between populations. We suggested that taxa in section Palmata should be considered as one species. Based on the research on the R. palmatum complex, we considered that the quantitative characteristics were greatly influenced by the environment. Therefore, it is not reliable to delimitate the species according to the continuously quantitative vegetative characteristics.     

Trachycarpus ravenii sp. nov. (Arecaceae,Corypheae) from central Laos

A new species Trachycarpus ravenii discovered in Kasi district, Vientiane province of central Laos is described and illustrated. Morphologically, it is closest to T. oreophilus and T. princeps, but differs by having a shorter stem of mature plants; glabrous, dull green petiole; almost circular leaf blade, waxy bluish–white abaxially; narrow leaf segments with narrow free lobes densely adpressed to each other, as well as in oblique‐round apices of median leaf segments.     

The correct nomenclature of the Nigerian species of Xanthosotna Schott (Araceae)

A literature survey showed that taxonomists retain both Xanthosotna sagittifolium (L.) Schott and X. mafajfa Schott as separate species. The diagnostic features of these species are clearcut as X. sagittifolium (L.) Schott has overlapping leaf lobes and a tapering male portion of the spadix in contrast to the divergent leaf lobes and symmetrical male region of the spadix of X. mafaffa Schott. Field studies indicate that features of the Nigerian members of the genus agree with those of X. mafaffa Schott which is the correct name of the Nigerian taxon.     

Aspidistra punctatoides sp. nov. (Ruscaceae) from limestone areas in Guangxi,China

Aspidistra punctatoides Yan Liu & C. R. Lin (Ruscaceae) is described and illustrated as a new species from limestone areas in southwestern Guangxi, China, near the border with northern Vietnam. It resembles A. punctata Lindl. in leaf size, a campanulate perianth densely covered with purple spots, lobes adaxially with two fleshy keels, and the peltate stigma, but differs by the stigma being adaxially truncate and densely papillate, and by the margin being 3‐ or 4‐lobed with lobes emarginate at apex.     

Spiradiclis quanzhouensis sp. nov. (Rubiaceae) from a limestone area in Guangxi,China

Spiradiclis quanzhouensis, a new species of Rubiaceae from northeastern Guangxi, China is described and illustrated. It is similar to S. umbelliformis, but can be distinguished by its rosulate habit, subglabrous stems, leaf blades that are pubescent on both surfaces, lanceolate purple‐pubescent stipules that are undivided or sometimes bifid in apical 1/3, an inflorescence with 2–4 flowers, lanceolate 4–5 mm long calyx lobes that are purple‐pubescent outside, a salveriform corolla that is light purple‐pubescent outside, a semi‐inferior ovary, and capsules that are light purple‐pubescent with persistent calyx lobes 5–6 mm, in fruit 2 × as long as capsule.     

Biosystematic Studies on Adenophora potaninii Korsh. Complex (Campanulaceae) III. Genetic Variation and Taxonomic Value of Morphological Characters

Adenophora potaninii Korsh．complex is a morphologically variable group including six species．As shown in many species in the genus Adenophora,the variability of many morphological characters in the complex under investigation is amazingly great,which brings difficulties in the delimitation and indentification of taxa．In the present study,six populations representing five species in the complex were systematically sampled to investigate the pattern of morphological variation within population and to detect the genetic basis of the variation with progeny tests and controlled crosses．The results are as follows： Great morphological variation within population is found (Fig.1),including characters such as leaf shape,teeth number and size of leaf margins,teeth number of calyx lobes,and indumentum on the surface of stems and leaves,which were previously considered as diagnotic．Systematic sampling and statistical analysis show that the differences in the above characters exhibit continuous patterns of variation within population (Fig．1,2),though they are highly correlated (Table 2)．From progeny testing and crossing between two contrast types of individuals (oblong,dentate and pubescent leaves vs．narrow,entire and glabrous leaves)it is evident that those characters show continuous variability in segregating progenies (Fig.3,4)and appear to be influenced by large numbers of loci with individually slight effects．Since most wild populations were highly heterozygous for those characters,the individuals in one extreme of variation can produce their variable offsprings including individuals similar to those in the other extreme (Fig. 3). This is also true for the indumentum density on stems and teeth number of calyx lobes. In this complex, A. biformifolia Y. Z. Zhao, A. bockiana Diels and A. polydentata P.F. Tu et G. J. Xu were described exclusively based on leaf shapes, teeth number of leaf margins and calyx lobes, teeth size of leaf margins, and indumentum on the surface of stemsand leaves. It is demonstrated, however, that the variation of those characters is of a quantitative nature and show no discontinuities. As a result, genetic analysis of diagnostic characters along with their sympatric distribution and same habitats, strongly suggest that A.biformifolia as well as A. bockiana and A. polydentata are actually the extreme individuals within A. wawreana and A. potaninii respectively and should not be recognized as taxa at any taxonomic level.     

Dionysia assadii sp. nov. (Primulaceae: sect. Dionysiopsis) from southern Iran

The new species Dionysia assadii (Primulaceae) from the Irano–Turanian region in Fars province, Iran, is described and illustrated. It is compared with its closest relative Dionysia esfandiarii Wendelbo and differs from it in leaf shape, leaf margin, hair density of leaves and other organs, shape of calyx and bracts, color of corolla and status of lobes, form and color of seeds, as well as the length of anthers and style in longistylous flowers.     

A Rapid Non-destructive Method for the Estimation of Leaf Areas in Cassava

A rapid and non-destructive method of estimating leaf areaswas required for detailed study of new cassava varieties. Theoutlines of leaves were traced in the field and leaf areas wereobtained with a planimeter. Variety Caricass 2 was chosen fordetailed study and 50 leaves of each lobe number (three to ninelobes per leaf) were measured. The length and width were recordedfor all lobes and correlations were made with leaf areas. Alllobe lengths and length x width were highly correlated withleaf area. It is therefore necessary to measure the length ofonly one lobe to get an estimate of leaf area. Comparisons ofleaves with five and seven lobes from Caricass 1, Caricass 3and a local variety showed that these varieties could be measuredin the same way and that the regression coefficient for Caricass2, Caricass 3 and the local variety were not significantly different.A common regression coefficient could be used to estimate leafarea on all three varieties. Manihot esculenta Crantz, cassava, root crop, leaf area     

Ceropegia thaithongiae sp. nov. (Apocynaceae,Asclepiadoideae) from northern Thailand and preliminary observations on impacts of climate change on its only known population

A new pendulous herb, Ceropegia thaithongiae Kidyoo (Apocynaceae, Asclepiadoideae), is described from northern Thailand. This plant is strictly endemic to Chiang Dao Wildlife Sanctuary and critically endangered owing to it living in an ecosystem affected by frequent natural disturbances. It is here described, illustrated and compared to the similar species, C. mairei. Both species have fusiform rootstocks, 1–2‐flowered cymes, deeply bifid outer corona lobes and linear, hairy inner corona lobes. However, the new species can be distinguished by its glabrous stem, leaf covered with hairs on both surfaces and glabrous corolla tube and lobes.     

Primulina moi sp. nov. (Gesneriaceae) from a limestone area in northern Guangdong,China

A new species of Primulina, P. moi, from Guangdong, China, is described and illustrated. It is similar to P. lijiangensis in leaf shape, but can be distinguished by several characters, such as base of corolla tube constricted, lobes of adaxial lip ovate, abaxial lip 3‐lobed from base, lobes elliptic or oblong elliptic with cuspidate apex, yellow corolla and filaments, two non‐adhesive anthers when corolla is open, adnate only before anthesis and 2 stamnoides.     

中国珍珠菜属(报春花科)一新种——右旋过路黄

对新种右旋过路黄Lysimachia dextrorsiflora X. P. Zhang, X. H. Guo &; J. W. Shao进行了描述和绘图。该新种产于中国安徽和福建, 因茎匍匐, 叶对生, 花黄色, 单生叶腋与过路黄L. christinae Hance近缘, 但其花冠裂片在蕾期右旋(顺时针)旋转排列(俯视), 花梗通常长于叶片与叶柄长之和, 花期4月初至5月初而不同。     

Viola lilliputana sp. nov. (Viola sect. Andinium, Violaceae), one of the world's smallest violets, from the Andes of Peru

A new violet species of Viola Sect. Andinium, Viola lilliputana, is described from a single dry puna locality on an extensive intermontane plateau southeast of Cerro Palla Palla in the high Andes of Ayacucho Department in southern Peru. This diminutive rosulate violet is evidently among the smallest in the world and probably one of the smallest terrestrial dicots. It belongs to a distinctive species group with pinnatifid leaves that is endemic to central and southern Peru, including V. hillii, V. membranacea and V. weibelii. The new species is similar to V. weibelii in its large, strongly adnate stipules, elongate leaf lobes and dilated unappendaged style with ventral stigmatic orifice. It differs conspicuously from all other members of the pinnatifid-leaved group in its conduplicate leaf blades, straight, mostly nonoverlapping, oblong-lanceolate to broadly elliptical lobes with obtuse to rounded apices, and large basally fused pedicel bractlets. Despite many new collections of vascular plants from the high Andes of Peru and northern Bolivia in recent decades, this distinctive new species is still known only from its type locality, collected on the Iltis-Ugent expedition from November 1962 to January 1963.     

KNAT1 induces lobed leaves with ectopic meristems when overexpressed in Arabidopsis.

Plant development depends on the activity of apical meristems, which are groups of indeterminate cells whose derivatives elaborate the organs of the mature plant. Studies of knotted1 (kn1) and related gene family members have determined potential roles for homeobox genes in the function of shoot meristems. The Arabidopsis kn1-like gene, KNAT1, is expressed in the shoot apical meristem and not in determinate organs. Here, we show that ectopic expression of KNAT1 in Arabidopsis transforms simple leaves into lobed leaves. The lobes initiate in the position of serrations yet have features of leaves, such as stipules, which form in the sinus, the region at the base of two lobes. Ectopic meristems also arise in the sinus region close to veins. Identity of the meristem, that is, vegetative or floral, depends on whether the meristem develops on a rosette or cauline leaf, respectively. Using in situ hybridization, we analyzed the expression of KNAT1 and another kn1-like homeobox gene, SHOOT MERISTEMLESS, in cauliflower mosaic virus 35S::KNAT1 transformants. KNAT1 expression is strong in vasculature, possibly explaining the proximity of the ectopic meristems to veins. After leaf cells have formed a layered meristem, SHOOT MERISTEMLESS expression begins in only a subset of these cells, demonstrating that KNAT1 is sufficient to induce meristems in the leaf. The shootlike features of the lobed leaves are consistent with the normal domain of KNAT1's expression and further suggest that kn1-related genes may have played a role in the evolution of leaf diversity.     

Spiradiclis glandulosa sp. nov. (Rubiaceae) from limestone areas in southern China

Spiradiclis glandulosa L. Wu & Q. R. Liu, a new species from limestone areas in southern China, is described and illustrated here. This new species is similar to S. umbelliformis, but can be distinguished from the latter mainly by its abaxial leaf blade with densely set yellow glandule‐like spots (vs abaxially pilosulous), calyx lobes oblong‐laceolate, ca 4–6 mm long (vs ovate‐triangular, ca 0.6 mm), corolla tube inside densely pubescent above the middle and onto lobes in both forms (vs inside with villous ring above base), and capsules villosulous (vs glabrescent).     

Rubia austrozhejiangensis sp. nov. (Rubiaceae) from Zhejiang,China

Rubia austrozhejiangensis Z. P. Lei, Y. Y. Zhou & R. W. Wang, a new species of Rubiaceae from China, is described and illustrated. The new species is similar to R. ovatifolia Z. Ying Zhang and R. argyi (H. Lév. & Vaniot) H. Hara ex Lauener, but differs from the former in having stems and branches cylindrical, not quadrate‐angled, long‐ovate to ovate‐lanceolate leaf blades, many‐flowered inflorescence, and smaller mericarps, 3–4 mm in diameter. In R. ovatifolia, stems and branches are quadrate‐angled, leaf blades ovate, ovate‐cordate to rounded cordate, and the inflorescences are sparsely flowered. Compared to R. argyi, the new species has cylindrical, not quadrate‐angled stems and branches, leaf blades that are long‐ovate to ovate‐lanceolate, 3–5‐veined, and slightly reflexed corolla lobes. In R. argyi, stems and branches are quadrate‐angled or winged, the corolla lobes are spreading, and the mericarps are 5–7 mm in diameter.     

Nanocnide zhejiangensis sp. nov. (Urticaceae: Urticeae) from Zhejiang Province,East China

Nanocnide zhejiangensis X.F. Jin & Y.F. Lu, a new species of Urticaceae from Zhejiang, east China, is described with illustrations. The new species is morphologically similar to Nanocnide japonica in having staminate inflorescence longer than leaves, but differs by having glabrous stems, petioles, peduncles and abaxial leaf surfaces, glabrous perianth lobes of staminate flowers, dorsally glabrous perianth lobes of pistillate flowers, and acuminate or solitary spinose–setaceous at the apex. Analysis based on ITS, atpF–H, atpB–rbcL and trnL–F sequences also demonstrate that Nanocnide japonica is the closest extant relative to the new species.