本文選題：杉木　切入點：種子園　出處：《中國林業(yè)科學研究院》2016年博士論文

【摘要】：杉木是我國主要的用材樹種,其種子園營建技術(shù)水平在我國林木良種選育體系中一直居于領(lǐng)先地位。目前杉木已全面進入第3代育種水平,但是第3代種子園良種供應(yīng)量尚不能完全滿足生產(chǎn)需求。由于早期建設(shè)的杉木1~2代種子園大都進入老化衰退期,如何采取有效的技術(shù)措施,使老齡衰退種子園母樹得以復壯,延長經(jīng)營期限,已成為林業(yè)科技工作者關(guān)注和亟需解決的一個技術(shù)問題�；诖�,本研究以廣西全州縣咸水林場1987年完成嫁接的杉木第1代種子園老齡衰退母樹為研究對象,研究截干后老齡衰退母樹的生理響應(yīng)、復壯效應(yīng)和經(jīng)濟效益,以期為杉木老齡衰退種子園的持續(xù)經(jīng)營管理提供科學依據(jù)。取得的主要結(jié)果如下:(1)杉木衰退母樹個體在截干后均具萌發(fā)能力,約4個月后即可萌發(fā)新枝。截面高度是影響新枝萌發(fā)的最主要因素,新枝萌發(fā)能力與截面高度呈反比,距基部越近越有利于新枝的萌發(fā)和生長。對截面進行覆膜保水,可使新萌嫩枝的存活率從40.0%提高到98.0%以上,提高幅度1倍以上。(2)截干后新萌枝條的葉片氣孔特征有顯著變化,其氣孔器長度和寬度一定時期內(nèi)隨枝齡增加呈增大趨勢,至枝齡3a時較未截干母樹分別提高2.2%~2.8%和2.6%~9.8%。研究同時發(fā)現(xiàn),葉綠素含量與枝條年齡呈正相關(guān)關(guān)系,枝齡越大則葉綠素含量越高,截干后新萌枝條的枝齡得到幼化,因而葉綠素含量較未截干的老枝低�？扇苄蕴�、淀粉和碳水化合物含量與枝條年齡亦呈正相關(guān)關(guān)系。超氧化物歧化酶(SOD)與枝齡呈正相關(guān)關(guān)系,隨著枝條年齡的增加而增加,而過氧化物酶(POD)則相反,其含量與枝齡呈負相關(guān)關(guān)系,此兩種酶在枝條中的活性表現(xiàn)為相互抑制的關(guān)系,呈此長彼消規(guī)律。(3)截干顯著促進新萌枝條的光合能力,相較于未截干母樹的老枝,截干后所萌發(fā)新枝的凈光合速率、氣孔導度、蒸騰速率和水分利用效率分別提高了123.9%、84.0%、51.8%和22.8%。研究也發(fā)現(xiàn),枝齡越小,其光合能力越強。從枝條方向看,東面枝葉的凈光合速率、氣孔導度和蒸騰速率均高于南面和西面兩個方向,南面次之,西面最差。因此在種子園實際經(jīng)營過程中,應(yīng)注意樹冠枝條的管理。(4)截干后,在8月生長旺盛期,母樹N、P、K、Cu、Zn、Fe和B含量分別平均提高15.3%、17.0%、27.0%、239.7%、62.9%、45.2%和46.3%;在12月生長減緩期,母樹N、P、K、Cu、Zn和Fe含量分別平均提高4.6%、11.9%、11.8%、19.4%、15.4%和37.1%,表明截干可以達到促進杉木母樹衰退個體復壯的目的。(5)截干可有效促進老齡衰退母樹恢復和提高球果產(chǎn)量的能力,種子質(zhì)量也得到明顯改善。母樹在截干后的首次掛果即比該種子園近3a產(chǎn)量均值有所增加,增加幅度為35.6%。球果果長和果徑分別提高2.9%和1.6%,種子千粒重、優(yōu)良度、發(fā)芽勢、發(fā)芽率和成苗數(shù)量等指標也得到顯著提高,提高幅度分別為17.1%、82.7%、134.4%、130.3%和24.9%。同時發(fā)現(xiàn),赤霉素含量與母樹或母枝年齡呈負相關(guān)關(guān)系,與未截干相比,截干母樹種子的赤霉素含量更高,提高幅度約12.6%,因而相應(yīng)的種子發(fā)芽效果更好。(6)在遺傳基礎(chǔ)相對一致的情況下,種子的播種品質(zhì)將影響子代造林的表現(xiàn)。截干母樹種子的播種品質(zhì)優(yōu)于不截干母樹種子,因而其造林效果相對較好,2a生和3a生時其樹高生長量分別提高了4.6%和8.7%。(7)杉木大齡種子園不改造、截干復壯和更新重建3種方式的中短期經(jīng)濟效益綜合評價結(jié)果顯示,截干模式最優(yōu),改造不到4a即可獲利且逐年超出未改造模式,短期的內(nèi)部收益率高達33.44%,是重建模式的2.5倍以上,表明截干改造大齡杉木種子園是更新改造過渡期間的一種有效方式。綜上所述,對杉木大齡種子園的衰退母樹采取截干處理,可使其新萌枝條得到幼化,葉片生理特征得到改善,不但其新萌枝條所結(jié)球果、種子產(chǎn)量得到提高,且種子的品質(zhì)、實際育苗和造林效果也得到相應(yīng)改善。因此,截干措施對杉木衰退母樹的生理響應(yīng)積極、復壯效應(yīng)明顯。本研究的結(jié)果有助于豐富我國林木種子園的實踐經(jīng)驗和理論體系。
[Abstract]:Chinese fir is the main timber species in China, the seed orchard level has been in the leading position in China's tree breeding system. At present, Chinese fir has entered the third generation breeding level, but the third generation seed orchard seed supply still can not fully meet the production needs. By 1~2 in the early construction of the Chinese fir seed orchard are enter the aging period of recession, how to take effective measures, make the aging of seed orchard trees to decline and rejuvenation, the extension of the term of operations, has become a technical problem of forestry science and technology workers to pay attention to and solve. Based on this, this study takes Guangxi County State salt water forestry centre completed in 1987 first seed orchard of Chinese fir trees for aging grafting recession the object of study, research on stem cutting after aging physiological responses of the declining trees, rejuvenation effect and economic benefits, in order to sustainable management of Chinese Fir Seed Orchard for aging decline To provide a scientific basis. The main results are as follows: (1) Chinese fir seed germination ability of individuals were out of recession in the stem cutting after about 4 months after germination shoots. The section height is the main factor affecting shoot germination, shoot germination ability and section height is inversely proportional to the distance, the closer the base is conducive to germination the growth of shoots. The section and coated with water, can make new adorable shoots improving survival rates from 40% to 98%, increased by more than 1 times. (2) after cut NEW Adorable branches of stomatal characteristics have changed significantly, the stomatal length and width within a certain period of time with increasing branch age increased, 3a is not to shoot age trees cut stem were increased by 2.2%~2.8% and 2.6%~9.8%. study also found that the relationship between chlorophyll content and shoot age, branch age the greater the higher chlorophyll content, cut dry after new adorable branches shoot age and immature, and leaves The chlorophyll content than the stem cutting old branch is low. The soluble sugar, starch and carbohydrate content of branches and age were positively correlated. Superoxide dismutase (SOD) and branch age positively relationship, increased with increasing branch age, and peroxidase (POD) on the contrary, the content was negatively correlated the relationship with the ages of the two, the activity of enzyme in the branches of the performance of the mutual inhibition, in this long elimination rule. (3) the stem cutting branches significantly promote the new adorable photosynthetic capacity, compared to the non stem cutting trees and old branches, net light cut dry after the shoot photosynthesis rate, stomatal conductance, transpiration rate and water use efficiency were increased by 123.9%, 84%, 51.8% and 22.8%. studies have also found that the branch age is smaller, the photosynthetic capacity is stronger. From the branch direction, the net photosynthetic rate of the East light leaves, stomatal conductance and transpiration rate were higher than that in the South and west two the direction of the south. 嬈′箣,瑗塊潰鏈，

本文編號：1669365