珍稀濒危植物蒜头果种子萌发特征与幼苗类型的研究  

Seed Germination Characteristics and Seedling Types of Malania oleifera, a Rare and Endangered Plant

作　　者：普甜 栗宏林 王娟 潘悦 张平芳 陈婉东 PU Tian;LI Honglin;WANG Juan;PAN Yue;ZHANG Pingfang;CHEN Wandong(College of Forestry,Southwest Forestry University Key Laboratory of National Forestry and Grassland Administration on Biodiversity Conservation in Southwest China,Kunming 650224,China;Eco-development Academy,Southwest Forestry University,Kunming 650224,China;College of Landscape and Horticulture,Southwest Forestry University,Kunming 650224,China)

机构地区：[1]西南林业大学林学院、西南地区生物多样性保育国家林业和草原局重点实验室,昆明650224 [2]西南林业大学绿色发展研究院,昆明650224 [3]西南林业大学园林园艺学院,昆明650224

出　　处：《西北植物学报》2023年第2期242-254,共13页Acta Botanica Boreali-Occidentalia Sinica

基　　金：国家自然科学基金(32160008);云南省重大基础专项-生物资源数字化开发应用(202002AA100007);云南省万人计划“云岭产业技术领军人才”专项(云发改[2018] 212号)。

摘　　要：以去除果皮后阴干的珍稀濒危植物蒜头果种子为材料,在温室大棚沙池内进行层积处理,从层积处理开始至子叶出土的不同萌发阶段,考察蒜头果种子发育形态、贮藏物质积累、酶活性以及幼苗类型等变化特征,初步探讨其种子休眠形成原因。结果显示:(1)蒜头果种子从解除休眠开始至萌发形成幼苗的过程约需195 d,其中幼胚的形态发育后熟约需75 d,随后30 d内是种子集中萌发的时期,其发芽率达到最高(53.33%);依据种胚发育形态的标志特征将此过程划分为7个阶段(S1~S7阶段):S1阶段种子未萌发,S2阶段种胚“露白”,S3阶段胚根突破种皮长超过1 cm, S4阶段下胚轴与胚根连接处形成弯钩结构,S5阶段“S”型胚形成及胚根前端膨大,S6阶段种子不仅具有膨大的胚根且已有侧根的分化,S7阶段子叶脱落,胚芽出土,真叶出现。(2)蒜头果种子在湿沙层积过程中,种胚胚长和胚率从S1阶段的(5.49±1.57)mm和(19.48±5.72)%分别增加至S6阶段的(67.92±2.94)mm和(240.75±15.29)%,胚率平均增加了12.4倍,显示蒜头果种子的胚需要经历后熟过程才能萌发,属于胚后熟型种子。(3)从种子生理指标看,随着湿沙层积时间的增加,种胚内可溶性蛋白含量、淀粉含量先降后升,可溶性糖和丙二醛(MDA)含量以及超氧化物歧化酶(SOD)及过氧化物酶(POD)活性总体呈先升后降的趋势,而同期胚乳的大小和形态没有明显变化,但其淀粉、可溶性糖、可溶性蛋白等含量以及SOD和POD活性总体呈下降的趋势。(4)种子胚率、萌发率与胚乳内可溶性蛋白含量、淀粉含量均呈极显著负相关关系(P<0.01),与可溶性糖含量呈极显著正相关关系。研究发现,蒜头果种子从解除休眠至萌发前内部发生了一系列的生理生化变化,包括胚乳中贮藏营养物质可溶性蛋白等大分子物质的降解和酶活性不断下降,为种胚完成后熟解除休眠进入萌发提供了物质和能量Rare and endangered M.oleifera seeds dried in shade after peel removal are used as materials, stratification treatment in greenhouse sand pond, different germination stages from stratification treatment to cotyledon excavation, we investigated the change characteristics of seed development morphology, storage material accumulation, enzyme activity and seedling type of M.oleifera, to understand the causes of seed dormancy. The results showed that:(1) it takes about 195 days for M. oleifera seed to germinate and form seedlings from the beginning of dormancy release. It takes about 75 days for the morphological development of young embryo to ripen, and then 30 days later is the period when the seeds germinate intensively, with the highest germination rate. This process can be divided into 7 stages(S1-S7 stages) according to the characteristics of the developmental morphology of the embryo: The seeds do not germinate at S1 stage;S2 stage seed embryo “exposed”;At S3 stage, the radicle breaks through the seed coat more than 1 cm long;At S4 stage, the junction between hypocotyl and radicle forms a hooked structure;The formation of “S” type embryo and the enlargement of the front end of radicle at S5 stage;At S6 stage, the seeds not only have enlarged radicles, but also have lateral roots;At S7 stage, cotyledons fall off, germ unearthed and true leaves appear.(2) M.oleifera seeds in the process of wet sand stratification, seed embryos length and embryo rate increased from(5.49±1.57) mm and(19.48±5.72)% during stratification at S1 stage to(67.92±2.94) mm and(240.75±15.29)% at S6 stage, the embryo rate increased by 12.4 times on average. It shows that the embryo of M. oleifera seeds needs to go through the post-ripening process to germinate, which belongs to the post-embryonic type seeds.(3) From the perspective of seed physiological indicators, with the increase of wet sand stratification time, soluble protein content and starch content in seed embryo decreased first and then increased, while the contents of s

关 键 词：蒜头果 种子萌发 种子后熟 种胚形态 生理变化 幼苗类型 

分 类 号：Q945.34[生物学—植物学] Q949.741.2