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1.
研究了云南省昆明市西山和丽江市玉龙雪山的粉叶小檗(Berberis pruinosa Franch.)叶、花瓣和果实特征的变异式样.粉叶小檗幼叶背面具明显的白色粉霜,而成熟叶,尤其是秋冬季的老叶,叶片背面的白色粉霜几乎完全脱落,并呈灰绿色.虽然粉叶小檗花瓣先端存在缺裂和全缘两种变异式样,但是这些变异式样在居群内是连续的...  相似文献   

2.
Nervilia pangteyana J. S. Jalal, Kumar & G. S. Rawat (Orchidaceae), a new species from western Himalaya (Uttarakhand), India is described, illustrated and compared with its closest relative. In addition, a key is given to distinguish between species of Nervilia in the western Himalayas.  相似文献   

3.
Corydalis nana Royle in the western Himalaya is found to be a complex of three species, including two hitherto undescribed. The true C. nana is a yellow-flowered species. The most common, greyish-blue or white-flowered species in the Sino-Indo-Nepal Himalaya, hitherto mistaken as C. nana, is a new species described here as Corydalis magni. An additional related species, Corydalis devendrae, characterised by tuberous roots and dorsally wingless/non crestate upper and lower petals is also described and illustrated from Uttarakhand state, India. A table comparing diagnostic characters, along with keys to taxa of the complex and a distribution map, are also included.  相似文献   

4.
Dendrobium hesperis (Seidenf.) Schuit. & P.B.Adams (Orchidaceae: Epidendroideae: Dendrobieae), an interesting but lesser‐known orchid, referred to in earlier literature as Flickingeria hesperis Seidenf., was formerly believed to be endemic to the Gori Valley (Uttarakhand), the westernmost orchid hotspot in the Indian Himalayas. Originally described from western Himalayas in 1982, this species was later discovered in Manipur in northeast India in 2014, thereafter reported from Laos in 2020. This note is intended to provide correct nomenclature and updated distribution of this taxon along with diagnostic features and illustration to aid its identification.  相似文献   

5.
Abstract Invasive species have been hypothesized to out‐compete natives though either a Jack‐of‐all‐trades strategy, where they are able to utilize resources effectively in unfavourable environments, a master‐of‐some, where resource utilization is greater than its competitors in favourable environments, or a combination of the two (Jack‐and‐master). We examined the invasive strategy of Berberis darwinii in New Zealand compared with four co‐occurring native species by examining germination, seedling survival, photosynthetic characteristics and water‐use efficiency of adult plants, in sun and shade environments. Berberis darwinii seeds germinated more in shady sites than the other natives, but survival was low. In contrast, while germination of B. darwinii was the same as the native species in sunny sites, seedling survival after 18 months was nearly twice that of the all native species. The maximum photosynthetic rate of B. darwinii was nearly double that of all native species in the sun, but was similar among all species in the shade. Other photosynthetic traits (quantum yield and stomatal conductance) did not generally differ between B. darwinii and the native species, regardless of light environment. Berberis darwinii had more positive values of δ13C than the four native species, suggesting that it gains more carbon per unit water transpired than the competing native species. These results suggest that the invasion success of B. darwinii may be partially explained by combination of a Jack‐of‐all‐trades scenario of widespread germination with a master‐of‐some scenario through its ability to photosynthesize at higher rates in the sun and, hence, gain a rapid height and biomass advantage over native species in favourable environments.  相似文献   

6.
7.
Xu CY  Griffin KL  Schuster WS 《Oecologia》2007,154(1):11-21
Early leafing and extended leaf longevity can be important mechanisms for the invasion of the forest understory. We compared the leaf phenology and photosynthetic characteristics of Berberis thunbergii, an early leafing invasive shrub, and two co-occurring native species, evergreen Kalmia latifolia and late leafing Vaccinium corymbosum, throughout the 2004 growing season. Berberis thunbergii leafed out 1 month earlier than V. corymbosum and approximately 2 weeks prior to the overstory trees. The photosynthetic capacity [characterized by the maximum carboxylation rate of Rubisco (V cmax) and the RuBP regeneration capacity mediated by the maximum electron transport rate (J max)] of B. thunbergii was highest in the spring open canopy, and declined with canopy closure. The 2003 overwintering leaves of K. latifolia displayed high V cmax and J max in spring 2004. In new leaves of K. latifolia produced in 2004, the photosynthetic capacity gradually increased to a peak in mid-September, and reduced in late November. V. corymbosum, by contrast, maintained low V cmax and J max throughout the growing season. In B. thunbergii, light acclimation was mediated by adjustment in both leaf mass per unit area and leaf N on a mass basis, but this adjustment was weaker or absent in K. latifolia and V. corymbosum. These results indicated that B. thunbergii utilized high irradiance in the spring while K. latifolia took advantage of high irradiance in the fall and the following spring. By contrast, V. corymbosum generally did not experience a high irradiance environment and was adapted to the low irradiance understory. The apparent success of B. thunbergii therefore, appeared related to a high spring C subsidy and subsequent acclimation to varying irradiance through active N reallocation and leaf morphological modifications.  相似文献   

8.
Xu CY  Schuster WS  Griffin KL 《Oecologia》2007,153(4):809-819
In the understory of a closed forest, plant growth is limited by light availability, and early leafing is proposed to be an important mechanism of plant invasion by providing a spring C “subsidy” when high light is available. However, studies on respiration, another important process determining plant net C gain, are rare in understory invasive plants. In this study, leaf properties and the temperature response of leaf respiration were compared between invasive Berberis thunbergii, an early leafing understory shrub, and two native shrubs, Kalmia latifolia, a broadleaf evergreen and Vaccinium corymbosum, a late-leafing deciduous species, in an oak-dominated deciduous forest. The seasonal trend of the basal respiration rates (R 0) and the temperature response coefficient (E 0), were different among the three shrubs and species-specific negative correlations were observed between R 0 and E 0. All three shrubs showed significant correlation between respiration rate on an area basis (20°C) and leaf N on an area basis. The relationship was attributed to the variation of both leaf N on a mass basis and leaf mass per area (LMA) in B. thunbergii, but to LMA only in K. latifolia and V. corymbosum. After modeling leaf respiration throughout 2004, B. thunbergii displayed much higher annual leaf respiration (mass based) than the two native shrubs, indicating a higher cost per unit of biomass investment. Thus, respiratory properties alone were not likely to lead to C balance advantage of B. thunbergii. Future studies on whole plant C budgets and leaf construction cost are needed to address the C balance advantage in early leafing understory shrubs like B. thunbergii.  相似文献   

9.
Genetic structure of four wild populations of two hill stream fishes Barilius bendelisis (Ham.1807) and B. barna (Ham. 1822) from Uttarakhand, India, was studied using RAPD markers. Eight selective primers provided distinct and consistent RAPD profiles in both the species, producing a total of 47 and 35 scorable bands in B. bendelisis and B. barna respectively. The bands in the range 666–4,830?bp were scored for consistent results. The RAPD profiles generated by all the eight primers revealed varying degrees of polymorphism (25.00–50.00?%). The average genetic diversity (h) was estimated as 0.1661 and 0.1606 among the four populations of B. bendelisis and B. barna respectively.  相似文献   

10.
Two new species belonging toMarasmius (Agaricales) are described and illustrated from eastern Honshu, Japan:Marasmius capitatus sp. nov. (sectionEpiphylli), forming capitate cystidia and small basidiomata with a membranous, white pileus and a minutely pubescent, filiform stipe without basal mycelium, was found on dead fallen leaves ofCryptomeria japonica; Marasmius nivicola sp. nov. (sectionGlobulares), having entirely white, collybioid basidiomata with a furfuraceous to pruinose stipe and distinctly intervenose lamellae, was found on leaf litter of broad-leaved forest.  相似文献   

11.
The new species Echinops sahyadricus is discovered and described from northern Western Ghats, India. It is endemic to the Maharashtra state and probably restricted to few high mountain peaks in Western Maharashtra. The new species is distinguished from the related E. echinatus by adaxially glabrous to sparsely elgandular hairy leaf surfaces, larger non-cornigerous synflorescences up to 9 cm in diameter and numerous (19–24) glabrous phyllaries up to 27 mm long. An identification key to all Indian taxa of Echinops, illustration and colour plates are provided.  相似文献   

12.
A recent phylogenetic study of langurs and leaf monkeys of South Asia suggested a reticulate evolution of capped and golden leaf monkeys through ancient hybridization between Semnopithecus and Trachypithecus. To test this hybridization scenario, I analysed nuclear copies of the mitochondrial cytochrome b gene (numts) from capped, golden and Phayre’s leaf monkeys. These numts were aligned with mitochondrial cytochrome b sequences of various species belonging to the genera Semnopithecus and Trachypithecus. In the phylogenetic tree derived from this alignment, the numts fell into three distinct clades (A, B and C) suggesting three independent integration events. Clade A was basal to Semnopithecus, and clades B and C were basal to Trachypithecus. Among the numts in clades A and C were sequences derived from species not represented in their respective sister mitochondrial groups. This unusual placement of certain numts is taken as additional support for the hybridization scenario. Based on the molecular dating of these integration events, hybridization is estimated to have occurred around 7.1 to 3.4 million years ago. Capped and golden leaf monkeys might have to be assigned to a new genus to reconcile their unique evolutionary history. Additionally, northeast India appears to be a ‘hot spot’ for lineages that might have evolved through reticulate evolution.  相似文献   

13.
Austrheim  Gunnar 《Plant Ecology》2002,161(2):193-205
Leaf demography and growth of six common, co-occurring woody plant species that varied in stature (tree vs. shrub) and leaf texture (sclerophyllous, coriaceous, malacophyllous) were examined in a subtropical savanna parkland in southern Texas, USA. We tested the hypotheses that, (a) leaves of plants with evergreen canopies would have longer life spans than those of deciduous species; (b) supplementation of soil moisture would decrease leaf life span in both evergreen and deciduous species; (c) species responses to increased soil moisture availability would be inversely related to leaf longevity; and (d) deciduous growth forms would exhibit a greater growth response to increased soil moisture availability than their evergreen counterparts.A variety of seasonal leaf habits (evergreen, winter-deciduous and summer-deciduous canopies) and leaf life spans (median = 66 to 283 days) were represented by the targeted species, but there was no clear relationship between seasonal leaf habit and leaf longevity. Among species with evergreen canopies, median leaf longevity ranged from short (Zanthoxylum fagara = 116 days; Condalia hookeri = 158 days) to long (Berberis trifoliolata = 283 days) but did not exceed 1 yr. In fact, leaf longevity in evergreen shrubs was often comparable to, or shorter than, that of species with deciduous canopies (Ziziphus obtusifolia = 66 days; Diospyros texana = 119 days; Prosopis glandulosa = 207 days). Augmentation of surface soil moisture had no detectable effect on median leaf life span in any species and there was no clear relationship between leaf longevity and species growth responses to irrigation. Contrary to expectations, species with evergreen canopies responded to irrigation by producing more leaf biomass, longer shoots and more leaf cohorts/year than did deciduous species.Species differences in the annual cycle of leaf initiation, leaf longevity and canopy development, combined with contrasts in root distributions and a highly variable climate, may allow for spatial and temporal partitioning of resources and hence, woody species coexistence and diversity in this system. However, the lack of expected relationships between leaf longevity, leaf habit and plant responses to resource enhancement suggests that structure-function relationships and functional groupings developed in strongly seasonal environments cannot be applied with confidence to these subtropical savannas and thorn woodlands.  相似文献   

14.
15.
Stellaria devendrae sp. nov. (Caryophyllaceae) is here described and illustrated from the Uttarakhand state of the Indian western Himalaya. It differs from the allied S. monosperma Buch.‐Ham. ex D. Don and S. paniculata Edgew. in having sub‐sessile, oblanceolate or obovate leaves with non amplexicaul, rounded to sub‐auricled leaf base; an inflorescence of a terminal, regularly and simply branched panicle of cymes; larger flowers (5–8 mm across); 5‐lobed floral disc; relatively larger sepals (4–7 mm long); petal lamina lobed for more than 1/2 to 4/5 of the lamina; filaments opposite sepals with prominent nectar glands at base; adjoining filaments not fused at base, and an inconspicuously reticulate‐papillate seed surface.  相似文献   

16.
Germination, growth and survival of green Berberis thunbergii and its purple ornamental form, Berberis thunbergii var. atropurpurea, were compared in five natural environments (full sun meadow, edge of woods, moist woods, dry woods, pine woods) to determine whether these two forms have a similar ability to naturalize. Berberis thunbergii and Berberis thunbergii var. atropurpurea had similar germination rates of about 25% at the end of 3 years. Most of the seed germination occurred in year one (89%), with a small amount of additional germination in year two (10%), and even less in year three (1%). Greatest germination occurred in the moist woods and full sun meadow sites and the least occurred at the pine woods site. Germination was reduced in the pine woods environment by the thick leaf litter layer present there. Barberry seedling survival during the first year was only 22% and survival dropped to 11.3% by the end of 2 years. Purple barberry seedlings had a lower 2 year survival rate than green barberry. There was no difference in seedling growth between purple and green barberry seedlings, but surviving seedling growth rates at the five environments were comparable. Seedlings achieved maximum growth in the edge of woods environment, but also grew well in the full sun meadow environment. At harvest, the full sun meadow had the greatest number of seedlings present, while no seedlings survived in the pine woods site.  相似文献   

17.
A comprehensive study of stem, leaf and petiole anatomy of 10 species of Strobilanthes from northern Western Ghats of India was carried out to identify characteristics which would enable species identification when flowering material is unavailable. In Strobilanthes, some species bloom annually, others are plietesials, i.e. they grow without blooming for several years and then produce huge quantities of flowers, release seeds and die. Therefore, alternative methods, such as anatomical characters, are essential to distinguish Strobilanthes species in their vegetative stage. We collected ten species of Strobilanthes for anatomical characterization. Under the bright‐field microscope, stem cross‐sections of different species were found to be undulate, quadrangular, quadrangular‐winged or terete. Study of the stem revealed a distinct outer and inner cortex, the distribution of cystoliths (CaCO3 crystals), raphides (CaC2H2O5 crystals) and sclereids which varied from species to species. Study of leaf anatomy showed structural variation and vascular bundle shapes that differed between the species. Leaf epidermal characters under light and scanning electron microscopy exhibited variation in characters such as stomatal index, stomatal length and width, stomatal type and presence of glandular and non‐glandular trichomes. The petiole anatomy was species‐specific, especially with respect to vascular bundle structure and the distribution of structures such as sclereids, cystoliths, sphaeraphides and tannin cells varied. Hence, unique anatomical features of the stem, leaf and petiole could be used as taxonomic characters to identify Strobilanthes species in a vegetative state.  相似文献   

18.
The Brassicas are an important group of crops in India yielding edible oils and many vegetables. For improving cultivated Brassicas, the wild relatives are of considerable value. The Brassica group of seed oil and vegetables comprises six cultivated species, out of which three are diploids and three are digenomic tetraploids. Brassica juncea is the major seed oil crop in India which can be improved for several traits by incorporating genes from its distant relatives. The early work in India relating to genome manipulation consisted of synthesis of B. juncea by crossing B. campestris with B. nigra, experimental resynthesis of Brassica species and non-homologous pairing and genetic exchange at the interspecific level. The alloploid species B. napus and B. carinata have not been successful in India due to agrometereological limitations. However, synthetic forms of B. napus have been produced which have a desirable maturity period with good yield potential. Also, through non-homologous pairing, pod shatter resistant B. napus has been obtained, B. napus ordinarily suffers from pod shattering. Similarly, synthetic forms of B. carinata have been derived from reciprocal crosses between morphotypes of B. oleracea and B. nigra and also through protoplast fusion of B. nigra with B. oleracea. Molecular analysis has revealed that one of the somatic hybrids had a novel cytoplasmic combination which carried B. nigra mitochondrial and B. oleracea chloroplast genomes. A range of wild and weedy species related to crop Brassicas possess extensive genetic variability. Work for utilizing this variability included hybridization between wild and crop species, analysis of chromosome pairing and induction of alloploidy. Among Brassicas of interest to India, protoplast culture and regeneration has been successful in the case of B. oleracea, B. juncea, B. nigra and B. carinata (cultivated species) and Eruca sativa and Diplotaxis muralis (related wild species). Polyethylene glycol mediated protoplast fusion has been the most commonly used method in India for producing somatic hybrids involving Brassicas. The eight somatic hybrids produced and studied showed that in the majority of cases the fusions led to symmetric hybrids combining the complete genomes of the donor species. For developing suitable male sterile lines, B. juncea, B. campestris and B. napus nuclei have been combined with the cytoplasm of six wild species and stable male steriles have been developed. Protoplast fusion methodology has been used extensively for improving these CMS by manipulating cytoplasmic organelles, including production of new combinations of cp and mt.  相似文献   

19.
Prickly acacia (Vachellia nilotica subsp. indica), a native of the Indian subcontinent, is a serious weed of the grazing areas of northern Australia and is a target for classical biological control. Native range surveys in India identified a leaf webber, Phycita sp. (Lepidoptera: Pyralidae) as a prospective biological control agent for prickly acacia. In this study, we report the life cycle and host‐specificity test results Phycita sp. and highlight the contradictory results between the no‐choice tests in India and Australia and the field host range in India. In no‐choice tests in India and Australia, Phycita sp. completed development on two of 11 and 16 of 27 non‐target test plant species, respectively. Although Phycita sp. fed and completed development on two non‐target test plant species (Vachellia planifrons and V. leucophloea) in no‐choice tests in India, there was no evidence of the insect on the two non‐target test plant species in the field. Our contention is that oviposition behaviour could be the key mechanism in host selection of Phycita sp., resulting in its incidence only on prickly acacia in India. This is supported by paired oviposition choice tests involving three test plant species (Acacia baileyana, A. mearnsii and A. deanei) in quarantine in Australia, where eggs were laid only on prickly acacia. However, in paired oviposition choice trials, only few eggs were laid, making the results unreliable. Although oviposition choice tests suggest that prickly acacia is the most preferred and natural host, difficulties in conducting choice oviposition tests with fully grown trees under quarantine conditions in Australia and the logistic difficulties of conducting open‐field tests with fully grown native Australian plants in India have led to rejection of Phycita sp. as a potential biological control agent for prickly acacia in Australia.  相似文献   

20.
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