干旱区生态环境知识资源中心(Arid): 荒漠植物梭梭和沙拐枣的花环结构及C4光合特征

Arid

	荒漠植物梭梭和沙拐枣的花环结构及C4光合特征
其他题名	KRANZ ANATOMY AND C4 PHOTOSYNTHETIC CHARACTERISTICS OF TWO DESERT PLANTS,HALOXYLON AMMODENDRON AND CALLIGONUM MONGOLICUM
	苏培玺1 ; 安黎哲 1; 马瑞君 2; 刘新民 1
来源期刊	植物生态学报
ISSN	1005-264X
出版年	2005
卷号	29 期号:1 页码:1-7
中文摘要	为了探讨梭梭(Haloxylonammodendron)和沙拐枣(Calligonummongolicum)适应高温强光荒漠环境的光合作用机构及特征,通过对其同化枝的解剖结构观察,delta13C值分析,以及气体交换测定表明:二者均具有花环结构(Kranzanatomy),肉细胞(Mesophyllcell)呈栅栏状,其内侧是维管束鞘细胞(Bundlesheathcell),小维管束与维管束鞘细胞相接.在栅栏组织和贮水组织中,梭梭具有形状巨大的含晶细胞;沙拐枣具有大量的粘液细胞.梭梭和沙拐枣同化枝的delta13C值分别为-14.3和-14.8,在不同生长季节和土壤水分条件下,二者的delta13C值变化在-14到-16之间.梭梭和沙拐枣的CO2补偿点分别为2mumol·mol-1和4mumol·mol-1,光饱和点分别为1660和1756mumol·m-2·s-1,表观光合量子效率分别为0.044和0.057molCO2·mol-1photons.这表明,广泛分布于我国荒漠地区的木本植物梭梭和沙拐枣为C4植物,其光合途径不随生长季节和水分条件的变化而改变.
英文摘要	The desert plants, Haloxylon ammodendron and Calligonum mongolicum , grow under extreme arid conditions that are associated with high temperatures and intensive radiation. Their true leaves are highly re-duced and the young annual shoots become photosynthetic organs. In order to provide a theoretical basis of ref-erence for restoring natural ecosystems of desert regions and maintaining the stability of protective ecosystems that surround oases, the cross sectional anatomical structure, stable carbon isotope ratio (delta13C) and photosyn-thetic characteristics of the assimilating shoots of these two species were studied. The study area lies in the northern part of the Hexi Corridor Region in Gansu Province at the southern edge of the Badain Jaran Desert. During the growing season (late May to early October in 2001) , we collected assimilating shoots and prepared samples for analysis. For light microscopy, samples of assimilating shoots of H. ammodendron and C. mongolicum were cut in late July and fixed in FAA (alcohol: formalin: glacial acetic acid; 90:5:5). Transverse sections of assimilating shoots of the two desert plants were observed and pho-tographed using a Nikon 1 671 CHR microscope. The stable carbon isotope ratios (delta13C) of assimilating shoots of the two plants were analysed using a MAT-252 mass spectrometer in the State Key Gas Geo-chemical Labo-ratory of the Lanzhou Institute of Geology, Chinese Academy of Sciences, and compared with other desert plants and the Q crop, Zea mays. The response of the net photosynthetic rate ( Pn ) of the in, vivo assimilating shoots of the two plants to different photon flux density (PFD) and CO2 concentration ( Ca) were measured using a LI-6400 portable photosynthesis system (LI-COR, Nebraska, USA) . The assimilating shoots were cut after measurements of Pn and their areas measured with the 11-3100 Area Meter. The difference in delta13C and A of leaves or assimilating shoots of different plants and the difference in delta13C values of the same plant deter-mined in different growth periods were analyzed by single factor variance analysis. If there was a significant dif-ference , various levels of multiple comparison tests were made using Duncan’ s new multiple range test. The results are summarized below. 1) Assimilating shoots of H. ammodendron and C. mongolicum have a layer of hypodermal cells and two layers of chlorenchyma on the stem periphery, i.e. an outer layer of palisade cells and an inner layer of bundle sheath cells. The central portion of the shoot is occupied by water stor-age tissue with the main vascular bundles located in the center. Central bundles are thus separated from Kranz-type cells by layers of water storage cells. There are some small peripheral bundles that have contact with bun-dle sheath cells. Mesophyll and bundle sheath cells contain chloroplasts. The chloroplast of bundle sheath cells contains starch grain, but the chloroplast of mesophyll cells does not contain starch grain. For H. ammoden-dron , some crystal-containing cells existed in mesophyll and water storage tissue. For C. mongolicum, many mucilage cells existed in the mesophyll and water storage tissues. These results demonstrate that these two species have Kranz anatomy. 2) The delta13C values of H. ammodendron and C. mongolicum were - 14.3%o and - 14.8%e, respectively, whereas the corresponding values of Caragana korshinskii, Nitraria sphaero-carpa , Hedysanan scoparium and Reaumuria soongorica were - 25. 8%e, - 25. 8%o, - 26. 4%o and -28.1%o, respectively. The delta13C values of the desert plants H. ammodendron and C. mongolicum were similar and were not significantly different from the delta13C value of maize. Under different growth periods and under high and low water conditions, the delta13C values of these two species varied between - 14%e to - 16%e. However, the desert plants C. korshinskii, N. sphaerocarpa, H. scoparium and R. soongorica, and oasis shelterbelt arborous species, such as Elaeagnus angustifolia, Populus gansuensis, and the oasis species, Populus euphratica, all had similar delta13C value which varied between - 25 %c 30%e. The stable carbon isotope discrimination of H. ammodendron and C. mongolicum was 5%o - 6%o which was similar to the C4 crop maize, while those of the other plants mentioned above were I6%o - 22%o. 3) The CO2 compensation point (CCP) of H. ammodemdron and C. mongolicum was 2 and 4 mumol·mol-1, respectively, and that of C. korshinskii was 91 mumol·mol-1. 4) The light saturation point (LSP) of H. ammodemdron and C. mon-golicum was 1 660 and 1 756 mumol·m-2·s-1, respectively, C. korshinskii was 1 267 fxmol·m-1s-1. 5) The apparent quantum yield of H. ammodemdron and C. mongolicum was 0.044 and 0.057 mol CO2·mol-1 photons and C. korshinskii was 0.02 mol CO2·mol-1 photons. It was concluded that H. ammodendron and C. mongolicum, which occur widely throughout the desert regions of China, belong to the C4 plant group. The two species have Kranz anatomy, their S C values of as-similating shoots were around - 15%o, their CO2 compensation points were less than 5 mumol·mol-1, their light saturation points were higher than 1 600 mumol·m-2·s-1, and their apparent quantum yield was over 0.04 mol CO2·mol-1 photons. The two species have their own special tissues in photosynthetic organs: H. ammoden-dron has some crystal-containing cells whereas C. mongolicum has many mucilage cells. Their photosynthetic pathways did not change during the growing season or under changing water conditions.
中文关键词	荒漠植物 ; 梭梭 ; 沙拐枣 ; 同化枝 ; C4植物
英文关键词	Desert plant Haloxylon ammodendron Calligonum mongolicum Assimilating shoot C4 plant
语种	中文
国家	中国
收录类别	CSCD
WOS类目	PLANT SCIENCES
WOS研究方向	Plant Sciences
CSCD记录号	CSCD:1906000
来源机构	中国科学院西北生态环境资源研究院 ; 西北师范大学
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/206872
作者单位	1.中国科学院寒区旱区环境与工程研究所, 兰州, 甘肃 730000, 中国; 2.西北师范大学, 兰州, 甘肃 730070, 中国
推荐引用方式 GB/T 7714	苏培玺,安黎哲,马瑞君,等. 荒漠植物梭梭和沙拐枣的花环结构及C4光合特征[J]. 中国科学院西北生态环境资源研究院, 西北师范大学,2005,29(1):1-7.
APA	苏培玺,安黎哲,马瑞君,&刘新民.(2005).荒漠植物梭梭和沙拐枣的花环结构及C4光合特征.植物生态学报,29(1),1-7.
MLA	苏培玺,et al."荒漠植物梭梭和沙拐枣的花环结构及C4光合特征".植物生态学报 29.1(2005):1-7.