珍稀保護(hù)植物光葉木蘭生殖生物學(xué)研究
發(fā)布時間：2019-01-01 12:18
【摘要】：光葉木蘭(Magnolia dawsoniana)是木蘭科木蘭屬的高大落葉喬木,特產(chǎn)于四川中部大渡河谷及青衣江流域,其自然分布種群數(shù)量小,繁殖更新能力弱,是四川省林業(yè)廳推薦優(yōu)先保護(hù)的極小種群野生植物之一。生殖是物種繁殖的重要環(huán)節(jié),因此對珍稀瀕危植物的生殖生物學(xué)研究迫在眉睫。因此,本研究以栗子坪國家級自然保護(hù)區(qū)野生分布的光葉木蘭為對象,對其開花過程、開花物候、雌雄蕊發(fā)育、傳粉特性和種子特征等進(jìn)行了研究,探討了瀕危原因,研究結(jié)果如下：1.光葉木蘭開花過程大致可以分為五個階段：(1)花蕾期；(2)初開期；(3)展瓣期；(4)盛開期；(5)凋謝期；光葉木蘭花期2-4月,單株開花持續(xù)34-42 d,群落開花持續(xù)47-52d,高海拔群落開花時間比低海拔群落晚近半個月。2.開花過程存在二次開合現(xiàn)象,單朵光葉木蘭花在第一天花被片展開后,在該天晚上花被片會稍合攏,第二天約10：00左右再次展開,此后,花被片完全保持展開不再閉合,直至脫落。3.光葉木蘭雌雄蕊異熟,雌蕊先雄蕊成熟12h；雌蕊及雄蕊的品質(zhì)都隨著時間的推移下降：雌蕊表現(xiàn)為可授性下降,雄蕊表現(xiàn)為花粉生活力下降、萌發(fā)時間增長、萌發(fā)率降低�；ǚ哿看�,可達(dá)2,047,500,花粉-胚珠比為2,6546.19,屬專性異交,需要傳粉媒介。4.光葉木蘭訪花昆蟲少,蜜蜂、蠅、甲蟲類、毛蚊科和薊馬科五大類昆蟲,訪花昆蟲訪花頻率低；花被片、雌蕊柱頭黏液、花粉在不同花期吸引的昆蟲有所差異,其中受花粉吸引強的昆蟲為蜜蜂、蠅和甲蟲。5.光葉木蘭花托中間部位的部分子房常敗育,果實常出現(xiàn)彎曲現(xiàn)象,結(jié)實率僅58.57%；種子質(zhì)量差,飽滿種子僅占46.33%,且飽滿種子生活力平均60.67%；種子中還有抑制種子發(fā)芽的物質(zhì)存在,不利于種子的萌發(fā)。綜上所述,導(dǎo)致光葉木蘭種群極小的主要原因是需要昆蟲為其傳粉但訪花昆蟲種類少且頻率低,傳粉效率低；花粉生活力低,且柱頭可授性時間短；結(jié)實率低、種子生活力低且種子含有抑制類物質(zhì)。
[Abstract]:(Magnolia dawsoniana) is a large deciduous tree of Magnoliaceae. It is specialized in Dadu River Valley and Qingyi River Valley in central Sichuan. Its natural distribution population is small, and its reproduction and regeneration ability is weak. It is one of the small populations of wild plants recommended by Sichuan Forestry Department. Reproduction is an important part of species reproduction, so it is urgent to study the reproductive biology of rare and endangered plants. Therefore, this study studied the flowering process, flowering phenology, pistil and stamen development, pollination characteristics and seed characteristics of Magnolia grandiflora, which was distributed in Liziping National Nature Reserve, and discussed the reasons of its endangerment, such as flowering process, flowering phenology, pistil and stamen development, pollination characteristics and seed characteristics, etc. The results are as follows: 1. The flowering process of Magnolia lanceolata can be divided into five stages: (1) bud stage, (2) initial opening stage, (3) spreading stage, (4) full bloom period, (5) withered period, and (3) flowering stage. The flowering time of the community was 47-52 days. The flowering time of the high altitude community was half a month later than that of the low altitude community. 2. There was a secondary opening and closing phenomenon in the flowering process. After the tepals of a single glossy leaf were spread out on the first day, the tepals would close slightly in the evening of that day, and then again around 10:00 on the next day. After that, the tepals remained completely unfolded and no longer closed. Until it falls off. The quality of pistil and stamen decreased with the passage of time, and the stamen showed decreased pollen viability, increased germination time and decreased germination rate. The amount of pollen is large, up to 2o 047g / 500, the ratio of pollen to ovule is 2 / 6546.19. it belongs to special heterosynthesis and needs pollination medium. 4. The floral visit insects of Magnoliaceae were few, and the insects of honeybee, fly, beetle, trichosphellidae and thripidae had low flower visiting frequency. Tepals, pistil stigma mucus and pollen attract insects at different flowering stages, among which bees, flies and beetles are strongly attracted by pollen. Part of ovary in the middle part of Magnolia grandiflora often aborted, the fruit was often curved, the seed setting rate was only 58.57, the seed quality was poor, the full seed was only 46.33, and the full seed viability was 60.67 on average. There is also a substance in the seed to inhibit seed germination, which is not conducive to seed germination. To sum up, the main reasons for the very small population of Magnolia lanceolata are that it needs insects to pollinate it, but the species and frequency of flowering insects are low, the pollination efficiency is low, the pollen viability is low, and the stigma can be pollinated for a short time. Seed setting rate is low, seed viability is low and seeds contain inhibitory substances.
【學(xué)位授予單位】：四川農(nóng)業(yè)大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：S685.99
本文編號：2397553
[Abstract]:(Magnolia dawsoniana) is a large deciduous tree of Magnoliaceae. It is specialized in Dadu River Valley and Qingyi River Valley in central Sichuan. Its natural distribution population is small, and its reproduction and regeneration ability is weak. It is one of the small populations of wild plants recommended by Sichuan Forestry Department. Reproduction is an important part of species reproduction, so it is urgent to study the reproductive biology of rare and endangered plants. Therefore, this study studied the flowering process, flowering phenology, pistil and stamen development, pollination characteristics and seed characteristics of Magnolia grandiflora, which was distributed in Liziping National Nature Reserve, and discussed the reasons of its endangerment, such as flowering process, flowering phenology, pistil and stamen development, pollination characteristics and seed characteristics, etc. The results are as follows: 1. The flowering process of Magnolia lanceolata can be divided into five stages: (1) bud stage, (2) initial opening stage, (3) spreading stage, (4) full bloom period, (5) withered period, and (3) flowering stage. The flowering time of the community was 47-52 days. The flowering time of the high altitude community was half a month later than that of the low altitude community. 2. There was a secondary opening and closing phenomenon in the flowering process. After the tepals of a single glossy leaf were spread out on the first day, the tepals would close slightly in the evening of that day, and then again around 10:00 on the next day. After that, the tepals remained completely unfolded and no longer closed. Until it falls off. The quality of pistil and stamen decreased with the passage of time, and the stamen showed decreased pollen viability, increased germination time and decreased germination rate. The amount of pollen is large, up to 2o 047g / 500, the ratio of pollen to ovule is 2 / 6546.19. it belongs to special heterosynthesis and needs pollination medium. 4. The floral visit insects of Magnoliaceae were few, and the insects of honeybee, fly, beetle, trichosphellidae and thripidae had low flower visiting frequency. Tepals, pistil stigma mucus and pollen attract insects at different flowering stages, among which bees, flies and beetles are strongly attracted by pollen. Part of ovary in the middle part of Magnolia grandiflora often aborted, the fruit was often curved, the seed setting rate was only 58.57, the seed quality was poor, the full seed was only 46.33, and the full seed viability was 60.67 on average. There is also a substance in the seed to inhibit seed germination, which is not conducive to seed germination. To sum up, the main reasons for the very small population of Magnolia lanceolata are that it needs insects to pollinate it, but the species and frequency of flowering insects are low, the pollination efficiency is low, the pollen viability is low, and the stigma can be pollinated for a short time. Seed setting rate is low, seed viability is low and seeds contain inhibitory substances.
【學(xué)位授予單位】：四川農(nóng)業(yè)大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：S685.99
【相似文獻(xiàn)】
相關(guān)碩士學(xué)位論文 前1條
1 孫燕;珍稀保護(hù)植物光葉木蘭生殖生物學(xué)研究[D];四川農(nóng)業(yè)大學(xué);2015年
，本文編號：2397553
本文鏈接：http://sikaile.net/shoufeilunwen/zaizhiyanjiusheng/2397553.html
最近更新
教材專著
