古尔班通古特沙漠南部短命植物群落物种多样性及空间分异

短命植物是早春多雨、夏季干热环境而形成的特殊植物类型,古尔班通古特沙漠南部是短命植物集中分布区,对保持沙漠稳定、防风固沙起到重要作用.目前对短命植物群落多样性、生态功能以及空间分布等研究较少.本研究采用分层抽样方法,调查分析了古尔班通古特沙漠南部35个样点3.86×104m2的短命植物多样性特征.共发现93个物种,分属...     

新疆的短命植物（一）独特的生态生物学特点

短命植物又称短营养期植物、短期生植物。它包括当年完成其生活周期、整个植株干枯死亡,来年春季再由种子形成新个体的一年生短命植物;也包括植株当年生地上部分枯死,而地下器官则处于休眠状态,到第二年春天既可由种子繁殖新个体,也能从地下芽生长出新植物体的多年生短命植物。前者称为短命植物,后者叫做类短命植物。原苏联的中亚地区,是短命植物区系的现代分布中心。在我国,它集中分布于新疆北部的山前平原及低山丘陵地带,是新疆植物区系组成的一个独特类群,在学术上和生产实践中都受到人们的关注。不同的植物适应环境的方式各种…     

特殊环境真菌

真菌是生物多样性最丰富和生存环境最多样的生物类群之一,除了我们熟知的土壤、植物残体、水体等一般环境外,还存在极地、高温、高盐等各种特殊环境.对真菌而言,特殊环境是指绝大多数真菌不能生存的环境,而特殊环境真菌是指特殊环境中特有的真菌或适应特殊环境的真菌.特殊环境人为地划分为以下3种类型:第一类,具有某种特定的理化限制因素的环境;第二类,某些特殊基质;第三类,受多因素限制的特殊复杂环境.特殊环境真菌有着独特的适应性,并进化出各种机制来占据生态位.它们在细胞构造、代谢方式、进化机制等方面的特殊性引起了科学家的广泛关注.本文介绍了各种特殊生态环境下生活的真菌类群以及它们的生存机制,并对今后的研究方向进行了展望.     

新疆准噶尔荒漠短命植物群落特征及其水热适应性

短命植物是一类利用短暂湿季快速生长的特殊植物类群, 包括一年生短命植物和类短命植物。作者在新疆北部准噶尔荒漠的莫索湾地区从2005-2008年进行了连续4年的群落调查研究, 通过25条样线201个样方的调查, 并结合同时段冬春季节的气温、降水资料, 探讨了短命植物对环境水热变化的适应性特征。结果表明: (1) 早春季节, 短命植物在准噶尔荒漠植物群落组成中占据优势地位, 物种数均占调查总物种数的52%左右; (2) 从群落优势种来看, 7种植物标准频度在40%以上, 其中6种是短命植物, 分别是旱麦草(Eremopyrum orientale)、卷果涩芥(Malcolmia scorpioides)、硬萼软紫草(Arnebia decumbens)、狭果鹤虱(Lappula semiglabra)、四齿芥(Tetracme quadricornis)和沙滨藜(Atriplex dimorphostegia); (3) 群落中短命植物萌发的个体数量与前一年冬季温度关系极为密切, 较低的冬季温度更易激发其萌发, 而当年群落外貌特征则更多地依赖于早春季节的降水, 若早春季节温度过低也会影响短命植物的萌发; (4) Shannon-Wiener多样性指数和Pielou均匀度指数年际间变化趋势与同期冬春降水总量变化趋势一致。总之, 温度和降水的不同配置是引起短命植物多样性发生年际变化的主要因素。     

新疆菊科短命植物异喙菊的解剖学研究

“短命”植物生活周期短,逃避干旱季节,是干旱区植被组成中一类特殊的草本植物。我国天山以北,古尔班通古特沙漠边缘生长有大量的短命植物。在这些地区年降水量虽少,但冬季有积雪,春季有一定的降雨:春夏期间,土壤湿润,为具浅根系的“短命”植物整个生长发育时期提供了十分有利的水份供应。尤其在冬季严寒已过,夏季酷热未到的春季,其气候可满足“短命”植物进行高效光合生产的需要,较大的日温差,     

胡卢巴属4种短命植物个体大小依赖的繁殖输出与生活史对策

 对准噶尔荒漠中胡卢巴属(Trigonella)4种短命植物网脉胡卢巴（T． cancellata ）、单花胡卢巴（T. monantha）、直果胡卢巴（T. orthoceras）和弯果胡卢巴（T. arc uata）的物候特征及生物量分配进行了比较研究,结果表明：1）这4种植物的萌发对策多样,具有春 、夏、秋萌现象,但以春、秋季萌发为主。其萌发时间在种间差异不明显,而与温度、降水等环境因子密切相关;2）生长发育快,生活周期短,一次结实,在干热夏季来临前完成生活周期,因此属于典型的避旱型植物;3) 秋、春萌株在早春返青或种子萌发后,经过短暂的营养生长后很快进入生殖生长,通过物候期（尤其是营养生长与生殖生长阶段）的迅速转换来获得高的繁殖力,最后达到较高的繁殖产量;4）繁殖分配比率均较高,分别达62.3%、51.9 %、54.3%和58.3%,且其繁殖输出与植株大小呈正相关;5）萌发时间不同的植株（春、秋萌 株）在大小及繁殖输出上差异显著,但繁殖分配比率差异不显著,说明由萌发时间差异引起的繁殖输出差异归根结底是由植株大小差异引起的。最后探讨了胡卢巴属这4种短命植物的生活史对策以及因萌发时间不同产生的植株在个体大小、生存力和繁殖输出等方面的差异对准噶尔荒漠干旱环境的适应意义。     

高山植物对其环境的生理生态适应性研究进展

高山林线植物(林木和草本)由于生长环境特殊而形成其独特的适应环境的生理生态特性.该文对近年来国内外有关高山植物、特别是林线林木在形态解剖结构、光合作用、养分利用和碳水化合物及抗氧化系统等方面对高山环境的生理生态适应性的研究进展进行综述,指出了林线树种生理生态适应性研究方面的不足,并提出了今后高山林线树种生理生态需要研究的方向,以期为研究气候变化下高山林线植物的应对策略和适应机制提供参考.     

类短命植物阿尔泰独尾草的解剖学研究

通过常规石蜡切片法,对类短命植物阿尔泰独尾草的根、茎、叶、花等器官进行了解剖结构的研究。结果表明：阿尔泰独尾草的根系有明显的二型性,即有储藏根和吸收根的结构与功能分化,是其对生长发育快速、年休眠期长的类短命植物生活习性高度适应的结果;其营养器官表现出明显的旱生植物特征;储藏根与吸收根木质部的二型性及其内皮层的带状凯氏带增厚结构则说明独尾草属植物可能具有较为特殊的系统演化地位。     

辽宁白石砬子保护区早春类短命植物研究

调查和分析了白石砬子保护区早春类短命植物物种组成的数量特征,应用物种丰富度指数、Shannon-Wiener多样性指数、Pielou均匀度指数、Simpson优势度指数,定量描述了不同林型下早春类短命植物的物种多样性.结果表明:研究区有早春类短命植物12种2变型,隶属7科11属.黑水银莲花是早春类短命植物层片的优势种.花曲柳林下早春类短命植物物种数最多,枫桦林、红松阔叶林、落叶松林次之,蒙古栎林、杂木林、鱼鳞云杉臭冷杉林最少.多样性指数的变化趋势总体上表现为针阔混交林>落叶阔叶林>针叶林.均匀度指数的变化与多样性指数的变化趋势基本一致,与优势度指数的变化趋势相反.红松阔叶林下早春类短命植物物种多样性最高且各物种均匀分布,层片结构稳定.     

被子植物地下结实和地上/下两型结实的生态适应意义

地下结实和地上/下两型结实是被子植物两类独特的结实方式, 多发生在陆生和草本植物中, 主要生长在缺少水分或光照、土壤扰动频繁及环境波动较为剧烈的生境中。两种结实方式不仅是植物适应性进化的重要方面, 也是选择性进化的产物。其中, 地下结实对于植物在母株附近适宜微环境中保存后代、在极端环境下保持种子活力、逃避地面动物取食和火灾伤害以及延长果实发育时间等方面, 地上/下两型结实对于减少同胞子代及种群内竞争、维持和扩大种群以及提高物种的适应力和进化可塑性等方面, 都具有重要的生态适应意义, 是植物抵御不利生物与非生物环境的两类重要防御策略。但两种结实方式同时也存在着限制果实与种子扩散、影响基因传递与种群遗传结构、加大种群隔离以及提高繁殖代价等进化限制, 对物种的分布、种群增长、迁移、适合度和生活史进化等具有重要影响。目前, 地下和地上/下两型结实现象分别在大约24科57属和13科34属中进行了报道, 其中在菊科、十字花科、豆科和玄参科等类群中两种结实现象同时存在。从系统发育看, 地下结实在木兰分支、单子叶植物分支及双子叶植物分支中均存在, 而地上/下两型结实仅出现在单子叶植物分支和双子叶植物分支中, 在被子植物基部类群(ANITA类群)中两种结实方式均不存在。该文对植物地下和地上/下两型结实的类型、系统进化、繁殖特性和扩散对策进行了介绍, 并对其生态适应意义进行了总结, 以期为深入研究植物结实的进化策略提供参考。     

Photoprotective Effects of D1 Protein Turnover and the Lutein Cycle on Three Ephemeral Plants under Heat Stress

To clarify the characteristics of photoinhibition and the primary defense mechanisms of ephemeral plant leaves against photodestruction under high temperature stress, inhibitors and the technology to determine chlorophyll fluorescence were used to explore the protective effects of D1 protein turnover and the lutein cycle in the high temperature stress of the leaves of three ephemeral plants. The results showed that the maximum light conversion efficiency (Fv/Fm) of the ephemeral plant leaves decreased, and the initial fluorescence (Fo) increased under 35°C ± 1°C heat stress for 1–4 h or on sunny days in the summer. Both Fv/Fm and Fo could be recovered after 8 h of darkness or afternoon weakening of the external temperature. Streptomycin sulfate (SM) or dithiothreitol (DTT) accelerated the decrease of Fv/Fm and the photochemical quenching coefficient (qP) in the leaves of three ephemeral plants at high temperature, and the decrease was greater in the SM than in the DTT treatment. When the high temperature stress was prolonged, the Y(II) values of light energy distribution parameters of PSII decreased, and the Y(NPQ) and Y(NO) values increased gradually in all the treatment groups of the three ephemeral plants. The results showed that the leaves of the three ephemeral plants had their own highly advanced mechanisms to protect against photodamage, which inhibited the turnover of D1 protein and xanthophyll cycle. This can damage the PSII reaction center in the leaves of the three ephemeral plants under high temperature. The protective effect of D1 protein turnover on heat stress in Erodium oxyrrhynchum and Senecio subdentatus was greater than that of the lutein cycle, while the protective effect of lutein cycle was greater than that of D1 protein turnover in Heliotropium acutiflorum subjected to heat damage.     

Reproductive diversity and survival of the potential annual Diplotaxis harra (Forssk.) Boiss (Brassicaceae) in Egypt

Diplotaxis harra is a common annual species in the desert of Egypt, The investigated population was located in Wadi Hof near Helwan city. Additional water in relatively wet years cause these ephemeral plants to live longer and become perennials. The species has ephemeral, modular and coppiced life‐cycles and may shift from a r‐ to a K‐selected strategy. The germinable seed bank represented 15,6% of the total seed rain, out of which only 0,03% established as adult plants. About 72.7% of the adult plants were ephemeral. 27.0% modular and 0.3% coppiced plants. The highest contribution of the seed rain came from modular plants and the lowest contribution from coppiced plants. The survivorship curve of the coppiced plants exhibited a combination of Deevey type I and III curves. The ephemeral and modular plants showed steep curves. In contrast to ephemeral plants, the coppiced plants attained the highest reproductive value and the lowest reproductive effort, while the modular plants demonstrated intermediate values. The active phonological cycle started earlier in coppiced plants than in the modular and ephemeral plants. The period from the start of vegetative growth lo shoot‐die back extends from mid‐December to early June in coppiced plants, from February to May in modular plants, and from late February to early May in ephemeral plants. The living stumps of the coppiced plants remained dormant during summer and autumn months. Seeds collected from coppiced plants attained high germinability and viability, while those from ephemeral and modular plants attained low values. Seed longevity was higher in the modular plants (> 10 yr) than in seeds of ephemeral and coppiced plants (7–8 yr). The high energy content of the seeds produced from different cohorts over ten years of storage enabled the population to maximize the germinability. viability and longevity of seeds despite the unpredictable environment. The potential annual behaviour of D. harra is mainly attained by the persistence of viable seed bank and root‐shoot stock. The ability to shift from a r‐ to a K‐selected life‐cycle, phenological variations among the different cohorts of the population, variations in seed longevity and energy content strengthen intra‐population interactions.     

四种短命植物若干生物学生态学特性的研究

 卷果涩芥(Malcolmia scorpioides)、四齿芥(Tetracme quadricornis)、长齿四齿芥(T．recurvata)和狭果鹤虱(Lappula semiglabra)为新疆北部常见的四种短命植物。本文从种子生物学、发育节律、株形和植株寿命等方面研究它们与生存环境的协调与适应。     

近30年古尔班通古特沙漠短命植物的时空格局

基于1985—1999年的GIMMS-NDVI数据和2000—2014年的MODIS-NDVI数据提取短命植物的时空格局,结合野外调查数据和1985—2014年气象站点气温和降水数据,从不同时空尺度上分析了古尔班通古特沙漠短命植物的时空变化及其对气候变化的响应。结果表明:(1)古尔班通古特沙漠中短命植物层片整体表现出物种组成简单,优势度高、多样性和覆盖度低等特征,且层片特征主要是由优势物种所主导,在早春至盛夏期间,由于短暂的生活史造成层片整体在物候上有一个明显的起伏差异。(2)沙漠中短命植物覆盖度最高的区域为南部和中东部,北部次之,西部最少。就时间变化趋势而言,受近30年早春温度和冬春降水增加的影响,短命植物覆盖的区域面积呈现出明显的增加趋势。(3)1985—2014年间3、4月温度和冬春两季降水量呈上升趋势,而反映短命植物长势的NDVI值与冬春两季降水量也呈正相关性,但就相关性程度而言,冬季降水量与NDVI呈显著性相关(P0.05,r=0.405),而春季降水由于时滞效应并未表现出显著相关性。     

冻融过程对荒漠短命植物种子萌发的影响

荒漠区冻融交替显著改变土壤温度和水分条件,并进一步影响荒漠植物种子萌发。为解析荒漠土壤冻融过程对植物种子萌发的影响,本研究以古尔班通古特沙漠4种典型短命植物[东方旱麦草(Eremopyrum orientale)、卵果鹤虱(Lappula patula)、尖喙牻牛儿苗(Erodium oxyrrhynchum)和条叶庭荠(Alyssum linifollum)]为对象,通过模拟不同温度和土壤水分及冻融循环次数对种子进行处理,对比分析冻融结束后4种植物种子萌发参数(发芽率、发芽势、发芽指数、种子活力)。结果表明,温度对4种植物种子萌发参数均无显著影响,而土壤水分和循环次数均有显著影响(水分仅对条叶庭荠无影响),且存在显著交互作用。冻融循环次数增加可促进冻融后的种子活力和种子萌发,尤其是在低水分条件下表现得更为显著。冻融期高土壤水分显著降低东方旱麦草的种子发芽率,对其他物种的影响受冻融次数和白天温度状况的调节。在相同土壤水分条件下,冻融期白天高温可促进种子萌发。总体来看,冻融对荒漠短命植物种子萌发有显著影响并存在一定的种间差异性,这将造成冻融期结束后不同物种的种子萌发和幼苗生长存在差异,进而影响荒漠区植物群落结构。     

Photosynthetic compensation by the reproductive structures in the spring ephemeral Gagea lutea

Growth and reproduction of spring ephemerals inhabiting deciduous forests progress simultaneously during a short period from snowmelt to canopy closure. To clarify the mechanism to mitigate the cost of reproduction, contributions of foliar and non-foliar photosynthetic products to seed production were examined in a spring ephemeral Gagea lutea. Leaf growth, foliar and non-foliar photosynthetic activities, and total assimilated products were compared among reproductive-intact, floral bud-removal, and vegetative plants. Translocation of current photosynthetic products to individual organs was quantified by ¹³CO₂-trace experiment. Bulb growth was compared between hand-pollination and floral bud-removal treatments. Finally, seed set was compared between intact, leaf-clipping, and bract-clipping treatments. Fruit-forming plants retained leaves longer than vegetative and floral bud-removal plants, but the assimilative contribution of extended leaf longevity was negligible. Carbon supply by bract photosynthesis was large enough for fruit development, while carbon supply by fruit photosynthesis was offset by the high respiration loss. Foliar photosynthetic products were largely transported to bulbs, while translocation to reproductive functions was negligible. Because the floral bud-removal increased the bulb growth, lack of reproduction could lead to more storage. The leaf-clipping had no effect on seed production, while the bract-clipping significantly reduced the seed production. Therefore, current photosynthesis of leafy bracts might be a major carbon source for fruit development. This self-compensative mechanism of reproductive structure enables the continuous reproductive activity in this species.     

Photomorphogenesis, photosynthesis, and seed yield of wheat plants grown under red light-emitting diodes (LEDs) with and without supplemental blue lighting

Red light-emitting diodes (LEDs) are a potential light sourcefor growing plants in spaceflight systems because of their safety,small mass and volume, wavelength specificity, and longevity.Despite these attractive features, red LEDs must satisfy requirementsfor plant photosynthesis and photomorphogenesis for successfulgrowth and seed yield. To determine the influence of galliumaluminium arsenide (GaAIAs) red LEDs on wheat photomorphogenesis,photosynthesis, and seed yield, wheat (Triticum aestivum L.,cv. ‘USU-Super Dwarf’) plants were grown under redLEDs and compared to plants grown under daylight fluorescent(white) lamps and red LEDs supplemented with either 1% or 10%blue light from blue fluorescent (BF) lamps. Compared to whitelight-grown plants, wheat grown under red LEDs alone demonstratedless main culm development during vegetative growth throughpreanthesis, while showing a longer flag leaf at 40 DAP andgreater main culm length at final harvest (70 DAP). As supplementalBF light was increased with red LEDs, shoot dry matter and netleaf photosynthesis rate increased. At final harvest, wheatgrown under red LEDs alone displayed fewer subtillers and alower seed yield compared to plants grown under white light.Wheat grown under red LEDs+10% BF light had comparable shootdry matter accumulation and seed yield relative to wheat grownunder white light. These results indicate that wheat can completeits life cycle under red LEDs alone, but larger plants and greateramounts of seed are produced in the presence of red LEDs supplementedwith a quantity of blue light. Key words: Triticum aestivum L., red light, blue light, subtillering, bioregenerative advanced life support     

外马廊山岛植被特性与植物多样性

该研究对无居民海岛舟山外马廊山岛进行初步踏勘,了解该岛植被特征与植物多样性,探讨海岛植被与大陆植被的差异性,并对海岛植物的主要植物组成、生活型结构、地理成分、群落类型以及多样性和相似性进行了分析。结果表明:外马廊山岛面积小,共有33科51属55种植物,植物种类偏少,留存有普陀狗哇花,滨柃,厚叶石斑木等具有滨海特色植物,具有开发潜力。外马廊山岛热带成分较为明显,与附近地区较为相似。岛上群落优势种或建群种的科为山茶科,大戟科,松科等,与大陆的常绿阔叶林的优势种或建群种的优势科如樟科,金缕梅科,壳斗科,山茶科等不大相同。岛上植物主要以高位芽植物为主(58.18%),但较大陆常绿阔叶林的高位芽植物比例要低。外马廊山岛植物群落结构简单,植物多样性相对较低,物种丰富较低,主要原因在于生态适应性和演替过程的差异,岛上植物群落演替至稳定群落还需要相当一段时间。外来种比例占9.09%,外来种如黑松和红鸡竹能形成群落或在群落中具有较为明显的优势,并可能会造成一定的生态干扰。     

Evaluation of a new culture method for mass-propagation of a photoperiod-temperature sensitive genic male sterile rice strain N19S

A newly established culture method was evaluated for application in mass-propagation of a photoperiod-temperature sensitive genic male sterile rice strain. It was found that the new culture method was very efficient for the regeneration of plants from callus of this strain, and a high concentration of 6-benzyladenine necessary for highly efficient plant regeneration culture did not seem to have negative effects on some agronomic traits investigated of the regenerated plants and their progenies. By the new culture method, a large number of plants could be regenerated in a relatively short time (approximately 8×10¹² plants within 300 days) from one naked seed-explant. Because of this, prominent drift of the PTGMS rice strain, which accumulates gradually during the course of propagation of the seeds through generations, in the response to photoperiod-temperature conditions could be avoided when this in vitro culture protocol is employed instead of seed propagation. Differences in rates of pollen fertility and seed setting were found between regenerated plants and seed-grown plants, and between their respective first and second progenies. These differences are also of important application value in two-line rice production: Higher pollen fertility of the regenerated plants can be applied with higher efficiency for the propagation of the strain seeds because they have much higher seed setting by self-fertilization; lower pollen fertility of the regenerated plant progenies will result in much lower seed setting by self-fertilization and is, therefore, conducive to the production of hybrid seeds of higher purity by natural crossing with the other line in the two-line system.     

Photomorphogenesis, photosynthesis, and seed yield of wheat plants grown under red light-emitting diodes (LEDs) with and without supplemental blue lighting

Red light-emitting diodes (LEDs) are a potential light source for growing plants in spaceflight systems because of their safety, small mass and volume, wavelength specificity, and longevity. Despite these attractive features, red LEDs must satisfy requirements for plant photosynthesis and photomorphogenesis for successful growth and seed yield. To determine the influence of gallium aluminium arsenide (GaAlAs) red LEDs on wheat photomorphogenesis, photosynthesis, and seed yield, wheat (Triticum aestivum L., cv. 'USU-Super Dwarf') plants were grown under red LEDs and compared to plants grown under daylight fluorescent (white) lamps and red LEDs supplemented with either 1% or 10% blue light from blue fluorescent (BF) lamps. Compared to white light-grown plants, wheat grown under red LEDs alone demonstrated less main culm development during vegetative growth through preanthesis, while showing a longer flag leaf at 40 DAP and greater main culm length at final harvest (70 DAP). As supplemental BF light was increased with red LEDs, shoot dry matter and net leaf photosynthesis rate increased. At final harvest, wheat grown under red LEDs alone displayed fewer subtillers and a lower seed yield compared to plants grown under white light. Wheat grown under red LEDs+10% BF light had comparable shoot dry matter accumulation and seed yield relative to wheat grown under white light. These results indicate that wheat can complete its life cycle under red LEDs alone, but larger plants and greater amounts of seed are produced in the presence of red LEDs supplemented with a quantity of blue light.