【作者】 吴彦琼；

【导师】 黎向东；

【作者基本信息】 广西大学 ， 生态学， 2002， 硕士

【摘要】 蒜头果为我国特有的常绿阔叶树种，被列为国家二级保护植物。经综合的调查、试验研究，表明其濒危的原因是内、外因素综合作用的结果。作者从植物的内因着手，寻找出导致种群濒危的关键环节，为挽救提供依据。 ①对开花习性、传粉机制进行实地观察，培养花粉对花粉活力、花粉管大小进行研究；②用不同贮藏材料作不同湿度范围的常温贮藏实验，摸索出最适贮藏湿度后用药物处理，观察种子贮藏状况并鉴定腐烂种病原菌；③通过冷藏研究低温对种子休眠的影响；④对根瘤作切片观察及营养元素含量分析。并采用实生育苗造林，进行扦插和组织培养试验，探索一种快速扩大蒜头果面积方法。 结果表明：(1)蒜头果花为两性花，属虫媒花；花粉培养的发芽率较低；花粉管生长速度较慢，且易弯曲，可能对授粉产生不良影响，结实率较低。(2)瘤状物的研究表明：该瘤是蒜头果根部组织的一部分；瘤内的养分含量与正常根的相差不大，初步断定其成因是由于微生物作用所致。(3)常温细砂贮藏，水分湿度以13％时保存效果较好，干藏种子因失水而失去活力，而太湿种子腐烂率很高。(4)3—5℃低温冷藏后种子萌发推迟，但种子在低温下推迟萌发的机制尚未清楚。(5)药物处理贮藏的种子效果极不理想，原因主要是种子的成孰度不够所致，药剂防病腐处理的研究尚有待进行。仿）从种子病腐组织分离、初步鉴定得6个种的病原真菌，镜检到一种线虫；人工接种发现茄类镰刀菌（Fusarium solani）等 3种是蒜头果种子的主要致腐疡菌，线虫的危害状尚未明睛。门）繁育实验显示，种子育苗有贮藏期间易腐烂、发芽率低、发芽后种植成苗率低的缺点，但在目前仍是主要的途径：营养繁殖的扦插处理长出不定芽，但没有不定根的分化；幼树茎段组织培养长出愈伤组织，也分化不定芽，但生长速度很慢且增殖困难；种胚培养能形成完整小植株，但生长较差，这方面尚有许多技术问题需进一步研究。更多还原

【Abstract】 Malania oleifera Chun et Lee , an evergreen broadleaves plant endemic to China , has beed ranked as the second-class protective spieces . Study showed it’s endangered mechanism resulted form interior factors integrated with exterior factors . The author analysed the inherent endangered mechanism to search an effective measure to save this plant.(1)Flowering characteristics and pollen disper mechanism of Malania were studied in the field and the pollens were cultured under the laboratory . (2)Sands with different humidity were used to store seeds . Petsicides were used to disinfect the material and seeds of the storage . The author periodicaly sampled the stored seeds and analyse aetiological agents . (3)Seeds were stored at low temperature to study the effect of low temperature on seeds’ dormancy. (4)The root nodule was chipped to examine under the microscope and it’s nutrition content was tested . Additionally , seeds’ generative reproduction were tried . Approaches of cutting and tissue culture were also studied to search an approach of increasing the area of Malania rapidly .The results are as follow : (1) The flower of Malania is hermaphrodite and the pollen dispersers are insets . The rate of the germination pollen cultured is very low . The pollens tube grow slowly and can be easily bent, which is possibly harm to pollination . The seed rate is very low . (2) The nodule is a part integrated to the root tissue . Nutrition contained in the nodules is similier to that of the root’s . It possiblly resulted from microorganism . (3) The storing result is best with the humidity of the sand is 13% . Seeds lose its’life while the humidity of storing sand is too dry and easily become rot while too wet. (4 ) Seeds stored at 3 -5 癈 condiction delay it’s germination . The mechanism that seeds delay it’s germination under low temperature is still unknown . (5 ) The protective rate of seeds disinfected with petsicides is low . The cause may be that seeds do not mature enough . (6) Separated from rot seeds’ tissue , 6 strains of pathogen and one eelworm have been purified . Artificicle inoculated test showed that Fusarium solani and the other two were the main fungus of the seeds . The symptom resulted form the eelworm is still unknown . ( 7 ) Test show seeding reproduction with low rate of germination and survive is still the chief ways at present. Stems of young tree used as explant cultured have adventitious sprout differentiation but don’t have adventitious root . Embryoes used as explant cultured can grow into an integrated plant but it grow poorly . All these technic required a deeper study .更多还原