Study On Physiological Genetics Of Cutting Propagation And Mineral Nutrition Of Masson Pine (Pinuns Massoniana Lamb.)

As a very important technology in forest tree improvement, tree vegetative propagation is paid the more attention to as the more the raw forest material is increasely needed by society and the more the intensive forestry develops. In order to mitigate the insufficient supply of improved seeds of Masson pine, avoid the differentiation of the characters in the generations of sexual propagation, further raise genetic gain, put an end to the state of improved trees propagated only by sexual technology, solve the problems of difficulty in cutting propagation and C-effect, and make genetic improvement get onto the rationalization track. Variation of the cutting rootability, cyclophysis, effect of rejuvenation, role of endogenous hormones, related oxidases and inhibitors, root-inducing technologies, geographic variation of mineral nutrition, correlation between mineral nutrition and growth of Masson pine, were studied, synthetically with the principles and methods of genetics, physiology, biochemistry, plant nutrition and mathematical statistics. Results as follows;1) The main reasons that Masson pine cuttings were difficult to root were, a type of induced root, low level of IAA , high levels of iPA , ABA, GA₁₊₃ and inhibitors (MIn). The root rate was also affected by the activities of lAA-oxidase (IAAO) and polyphenoloxidase (PPO). MIn were purified by extraction and HPLC, and biologically detected with wheat coleoptile section and the seeds of Pinus yunnanensis Franch.. All MIn were composed of seven components, four of them were tentatively identified as flavoniods and three of them phenols. MIn were controled by genes. Root rate would be raised as the expression of the genes were inhibited. The correlation between the total length of adventitious roots and the diameter of the longest root was the closest (r=0. 9314), but the sum of the adventitious roots and the branch roots negatively correlated (r= — 0.3687).2) Except the diameter of the longest root, variations of the time for callusing and rooting , and the other five root characters of cuttings from same age ortets of five provenances were notable. Variances of the root effective indexes consisted with root characters. Levels of endogenous hormones and MIn, activities of IAAO and PPO were also analysed. To make a comprehensive survey of all analyses, Tongmiang provenance in Guangxi Provincewas the best, and Jian in Jiang xi Province was the worst. However, the potentialities of individual selection in Jian provenance was large as the dispersion was the largest. Low specific activity of PPO in cuttings from Shaoguan provenance in Guangdong Province was one of the main reasons why they seriously rotted.3) Variances of the levels of endogenous MIn, IAA , iPA, ABA and GA1+3 in ten single trees from Jian provenance were notable. By theoretical inference, the rootability of NO. 3 tree would be highest, and the NO. 9 be lowest.4) Except the diameter of the longest root, the cyclophysis was found in time for cal-lusing and rooting, and the other five root characters. Root effective index of cuttings from two years old ortets was the highest (0. 646), and that from eight years old ones was the lowest (0. 056). One of the important reasons was MIn increasing as the ortets became older. But those cuttings from the ortets, younger than four years old, showed no cyclophysis. Therefore, using the seedlings of the half-sib or the full-sib families as the Masson pine ortets was proposed.5) Root characters of cuttings from stecklings were better than those from seedlings. Relative contents of MIn in cuttings from stecklings were lower than that from seedlings. All these indicateded that serial cutting rooting could inhibit the expression of MIn genes. By this way, the maturation of the ortet could be eased up.6) The lowest root rate cuttings from the ortets of Jian provenance were treated with 23 kinds of root-inducing treatment including CK. Tow root-inducing regulators (Mi and M2) , compounded by the author, increased the level of endogenous IAA , lowered the levels of iPA, ABA, and GA1+3, and also weadened the activity of IAAO. As a result, the root rate was raised from 34 percent (CK) up to 90 percent and 84 percent respectively. The best concentration of IBA for root-inducing was 200 ppm, and S3307 was 100 ppm. The theory of phasic function of plant regulators in the process of cutting rooting drawn out by Jarvis (1986) was verified with xylophyta for the first time.7) 25 mineral elements in the needles of ten provenances were studied during dormancy with inductively coupled plasma quantometer (ICP). The order of the total contents was, K >Ca>Mg>P>Al>Na>Si>Mn>Fe>Zn>Li>Sr>Cu>Ba>Ni>Ti>Pb>Co>Cr> Cd>V>Mo=Be=Se=As(contents of Mo, Be, Se and As were lower than the determination range of ICP). Dispersion of the most elements in provenances was large, so the potentiality of selection efficient nutrient genotypes was large. Variances of the most elements a-mong provenances were notable. Their contents negatively correlated with the latitude and longitude of the provenances. Long-term geographic adaptability made Masson pine absorb more Ca, Al, Na and Si, and that; formed the theoretical bases of the strong hardiness with adversity.8) Correlation between mineral elements and the growth of height and diameter wasanalysed. The result indicated that using the content of mineral elements of ever-green conifer trees during dormancy to analyse the level of mineral mutrition was reasonable. Contents of Ca and Zn in needles could be the early prediction factors for the growth of height and diameter by step wise regression analysis. The equatious as follows, Yh=0. 7547+3.1120X10"'Xc.-6. lmxlO-^a, (R = 0. 9541) Yd = l-9837+3. 4451 XlO-'Xc-O.llSOXa (R = 0.9474>By theoretical inference > Masson pine was one kind of high-Ca-absorption and high-Zn-uti-lization species.