Plants and the person. Future woods

you are: Plants and the person

Until recently wood did not grow up, but only cut. With increase in requirement for wood and a paper escalating value began to get cultivation of fast-growing tree species. As woods usually happen very much, the mixed genetic origin, intensive selection and crossing are necessary for deducing of fast-growing breeds of trees. main problem thus consists that many tree species ripen and are reproduced slowly. If it will be possible to find or create fast-growing kinds of trees how to develop the program of their crossing which would keep within acceptable time limits? And how it is possible to make multiple copies the created material quickly to receive so much trees, how many it is necessary that they have covered the area in hundred thousand hectares? The physiology of plants has allowed to solve some of problems facing to us, having created quickly growing, quickly ripening tree species steady against illnesses, in particular the coniferous. These new types of trees reach the sizes at which they can be used, several times faster, than before. Though fast growth usually reduces durability of wood for the building purposes, tree species of new lines are ideally suited for paper manufacture for which the weight of made wood is important only. one of problems consists that such coniferous breeds are very difficult for making multiple copies shanks as they badly take roots, and at reproduction by seeds it is impossible homogeneous population with desirable signs. All is wider an applied method of fabric cultures has allowed to receive in some cases new clones sejantsev, genetically identical to an initial tree of desirable type. Though attempts to make multiple copies all tree species with desirable signs by means of fabric cultures not always were successful, it is possible to assert with confidence that in the near future this method becomes standard for many lines of tree species.

For the further improvement of genotypes of tree species it is necessary to continue standard programs of crossings. It is at a loss that coniferous, like many other tree species, possess long juvenilnym the period previous approach of a maturity and flowering. The juvenilnyj period at some kinds can proceed till twenty years, and sometimes and longer if conditions of environment, for example plentiful loss of deposits, favour to vegetative growth. recently it has been established that juvenilnyj the period at the coniferous is regulated by changes of their nature endogennyh, gibberellinov and that therefore by means of some of these hormones it is possible to accelerate approach of a sexual maturity. Gibberellovaja acid (GKz), i.e. Usual available on sale gibberellin, it is effective only for some kinds which are not belonging to Pinaceae - to the family including the majority of the most valuable tree species. Moreover, at duglasii high maintenance GKz is connected with juvenilnym the period, instead of with the period of a sexual maturity. Recently it was found out, however, that at such trees with maturity approach the maintenance not polar gibberellinov increases; by means of these gibberellinov it is possible to induce reproductive activity even at four-year trees. Now to receive such gibberelliny it is difficult and consequently they cost much, however it is necessary to expect that their manufacture will extend, and the price will go down, as their practical value now is shown. Already it is possible to get a mix effective not polar gibberellinov ГК4 and ГК7; optimum results turn out at continuous introduction of these gibberellinov in plants throughout long time through a tube.

Having induced reproductive activity, it is possible then to regulate even number and a floor of cones. Long light day favours to development man's, and short - to development of female cones; influence by a cold often raises the general production of cones. At last, production of seeds can be accelerated, applying in a combination with not polar gibberellinami such auksin, as NUK.