化香的種子特性和光合特性的初步研究

（化學(xué)與生命科學(xué)學(xué)院，生態(tài)學(xué)實(shí)驗(yàn)室）

（此論文約10000字）

摘要：本文主要研究胡桃科化香屬落葉喬木化香( Platycarya strobilacea)的種子特性和光合特性，得出了很有價(jià)值的結(jié)論。（1）對化香種子進(jìn)行千粒重、發(fā)芽率和生活力的測定，并分析了測定結(jié)果和方法，對化香種子的特性有了初步了解。在研究過程中發(fā)現(xiàn)，化香種子存在休眠現(xiàn)象。分別用切除種皮、沙藏法、6-BA（細(xì)胞分裂素）、NAA（萘乙酸）、GA-3(赤霉素)處理化香種子，發(fā)現(xiàn)GA-3能夠很好地解除種子休眠而切除種子種皮、沙藏法、6-BA、NAA則不起作用。（2）通過設(shè)置4個(gè)光照梯度（25%，12%，6%，3%自然光）模擬鄂東南低山丘陵地區(qū)落葉闊葉林下的光環(huán)境并設(shè)置了兩個(gè)氮濃度（3mmol/l,15mmol/l),研究了化香幼苗的光合特性，用非直角雙曲線模型擬合得到了光響應(yīng)曲線特征參數(shù)。結(jié)果表明：隨著透光率的增加，最大光合速率Amax增加。但是不同濃度的氮處理對化香幼苗的最大光合速率Amax沒有顯著影響。暗呼吸速率Rd在12%透光率時(shí)達(dá)到最大，在25%時(shí)呈下降趨勢。不同濃度的氮處理對化香幼苗葉子的暗呼吸速率Rd依然影響不顯著。

關(guān)鍵字：化香；種子特性；種子休眠；光合特性；非直角雙曲線模型

The preliminary study on Seed characteristics and Photosynthetic characteristics of Platycarya strobilacea

Student：WangYuan

Instructor：Chuanhua Wang

Abstract:This study mainly study the seed characterristics and photosynthetic characteristics of Platycarya strobilacea of Juglandaceae Platycaryapollenites,we obtain a lot of valuable conclusion.(1)Thousand-grain weight,percentage of germination,viability of Platycarya strobilacea.We analyzed the results and methods and had an initial understanding of Seed characteristic of Platycarya strobilacea.During the research,we found that ,the seed of Platycarya strobilacea has dormancy.When we use sand harboring,6-BA,NAA and GA-3 to treat the seeds,we found that GA-3 can release the dormancy of the seeds,but sand harboring,6-BA and NAA don't work.(2)We researched the photosynthetic characteristics of Platycarya strobilacea under four controlled light regimes(3%,6%,12% and 25% natural irradiance and tow nitrogen concentration(15mmol/l and 3mmol/l). The characteristic parameters of light response curve was fitted by non-rectangle hyperbola model.Simulation results show that the maximum photosythesis rate Amax will increase when light regimes increase,but different nitrogen concentration does't have remarkable effect on the maximum photosythesis rate Amax.The dark respiratory rate Rd reach the maximum when the light regime is 12%,but the dark respiratory rate is on a declining curve when light regime is 25%.Different nitrogen concentration still does't have remarkable effect on dark respiratory rate.

Key Words:Platycarya strobilacea; seed characterristics; seed dormancy; photosynthetic characteristics;non-rectangle hyperbola model