1991 Vol. 4, No. 4
Transforming the low-yielding plantation of oil-tea camellia is a part of the Agricultural Program on Intergraded Development in China, and it is also an important measure to increase the production of oil-tea camellia in China.In order to quarantee the quality of the project and popularize advanced technology, we have raised ten suitable measures of transforming low-yie-lding oil-tea camellia on the basis of a systematic analysis of the low-yielding reasons. The technical tactics and measures of intergraded transformation have also been put forward: effect a permanent cure and take stopgap measure; ameliorat the framework of tree and forest stand on the basis of improving varieties; defend and raise soil fertility.
Based on the data of biomass and stem analysis of 20-year-old Bruguiera gymnorrhiza, the grey model(1,1) in the grey system theory is used to forecast the individual organ biomass of the tree and their precisions predicted of the grey model(1,1) are compared with those of the nonlinear regressive equation. The results show that grey model(1,1) can be used to predict accurately but the nonlinear regressive equation, owing to the existing major error, can not be applied. Biomass forecast in the near future is made in order to provide a theoretical basis for managing and utilizing Bruguiera gymnorrhiza stand rationally.
Since the rate of oil content pressed from the crude juice in the fresh fruits of H. rhamnoides L. subsp. turkestanica Rousi is up to 4.8%, in this study, according to the differences among the specific weights of oil, juice, residue, and the demands for processing conditions of products, including its yield and quality, the following technological effects have been achieved by breaking class by class, draining off residue, three-phase separation, as well as controlling the processing temperature, flow rate, concentration and granule size etc. They are as follows: The percentage of flesh oil yield separated from crude juice is 2.69%, which is 55% of oil contained in crude juice. After separation,0.03%~0.35% of oil content, 90% of the preservation of vitamine C, 4%-7% of solid material content, and the granules with average diameter of 3~5μm, still remained in the crude juice. In jam material, the percentage of solid material and of oil content are 23% and 7%~9% respectively.
This paper analyzed the growth of Pinus caribaea plantations of 5-year-old at two sites in the east and northwest of Hainan Island. The experimental results showed that the growth of P. caribaea between two sites were different significantly. P. caribaea in the northwest performed better than that in the east. The growth among the three varieties of P. caribaea in two sites also performed differently. On the rich soil with thick soil layer in the northwest of Hainan Island where P. caribaea var. caribaea and P.caribaea var. bahamensis had best performance, their increments in diameter, tree height and volume were superior to P. caribaea var. hondurensis. While on relatively meager soil in the east, P. caribaea var. hondurensis grew better.
A diallel cross, including selfs and reciprocals, of eleven Chinese Fir (Cunninghamia lanceolata) parents was analyzed. Analysis of eight-year data revealed that there is a similar genetic variation model for height (HT), diameter at breast height (DBH), volumn (VOL), and wood specific gravity (SG). Significant general combining ability as well as maternal effects were obtained. But specific combining ability, male effects, specific reciprocal effects seem to be negligible. These results suggested that besides significant additive genetic variance, there exist significant cytoplasm inheritance phenomenon. No significant genetic correlation between VOL and SG was obtained. Discussions on the analysis models of diallel and combining ability effects were made.
It has been shown by the dissection of embryo that the embryonic development of the lac insect, Kerria chinensis Mahd., may be divided into nine stages. For the convenience of its application in lac production the embryonic development may also be simplified into 6 stages, that is,1st stage——vitellarium disappeasing; 2nd stage——yolk cell globhing; 3rdstage——protopod; 4th stage——polypod; 5th stage——oligopod; and 6thstage——larva formation.It has been proved that the advancement of the embryonic development is closely related to larvae swarming and vitality of the following generation. It is appropriate to cut stick broodlac at the 5th stage with the developing embryos of this stage accounting for 90% in situ or for transportation within short distance. For distribution of broodlac to far distance the percentage of the embryos at 5th stage must reach 50%. Allocation of millions of kilograms of broodlac to southern provinces of this country has justified the criteria suggested during more than two decades of years.
The test on the spreading of pine wood nematode through wood chips was carried out in the Pacific Forestry Centre of Canada in 1988. The results show that the nematode can go out from the chips to cause pine seedling wilt and wounds are very important for this. One population of pine wood nematoes from Ontario can cause the seedlings wilt without any wounds. This phenomenon gives evidence that pine wood nematodes can panetrate immediately from roots or stem base of seedlings. The pathogenicity of populations from different locations is different.
The characteristics and different developmental stages in the embryogeny of Pseudolarix kaempferi (Lindl.) Gord. were investigated based on two previous papers, which are "The morphology and structure of stam-inate strobilus and the formation of microspore and male gametophyte in Pseudolarix kaemferi" and "The morphology and structure of femineus strobilus and the formation of megaspore and female gametophyte in Pseudolarix kaempferi". Pollen matures in early to middle April which is the time for pollination and germinates on nucellus in May. Later, two sperm nuclei move into pollen tube and archegonium forms at the same time. The egg cell in archegonium matures gradually. The zygote produces new cytoplasm, and subsequently develops from 4, 8, 16-cell proembryo to spherical one after the fertilization in June. The suapensor prolongs and the embryo proper enlarges in July. The root tip of embryo differentiates first, and then the shoot apex. Young embryo elongates, develops and differentiates further from Augest to September. The embryo matures in October, which conforms to simple polyembryony. The proembryo of P. kaemferi is referred to Pinus type.
Snow mould of spruce was reported for the first time in Western Tianshan in this paper. In some forest area of Aletaishan and Western Zhungeer Mountains, 41%~62% of the spruce seedlings was damaged by the disease, which was caused by the pathogens: Botrytis cinerea Pers., Sclerotinia sclerotiorum (Lib.) de Bary and Truncatella angustata (Pers. ex Lk) Hnghes. T. angustata is a new species recorded for the first time in China. Biological characteristics of the pathogens and the pathoginicity test have been conducted both in the field and in the lab. in Kaxi Nursery, Gongliu Forest Region. In the field, Microcomputer Figure Collection System was used to observe the temperature dynamics in the layers of snow and soil. Deep snow covers the ground from fall to late spring, so that the soil does not freeze at that time, which provides a suitable condition for the development of snow moulding.
Camponotus japonicus Mayr nests under ground. In one colony, there are eggs from 0 to 953, larvae from 29 to 2 302, pupae from 0 to 1 357, workers from 42 to 4 012 and dealate females from 1 to 3. The males and females usually appear in autumn and they will come out for marriage flight from last ten days of April to the first ten days of May next year. The growth time from egg to adult is as follows: 16 to 19 days for eggs, 10 to 28 days for larvae, 6 to 7 days for prepupae and 14 to 19 days for pupae. Placing larvae of the Dendrolimus punctatus Walker in the near of the ant, the ratio of 1 to 3 instar larvae by ants is 70%, 23.3% and 10% respectively. When the first and second instar larvae on trees were found by the ant, they will be preyed by 48% and 10% respectively. After 14 days experiment, the populations of the D. yunctatus in trees with ants decreased than those without ants by an average rate of 23.7%.
Obviously the most important factor to determine the differentiation of the Pine Caterpillar in the second generation is photoperiod experienced in its early larval period and the differentiation is associated with its population dynamics in nature along the Yangtze River area. The ratio of the third generation produced in field is closely related with the hatching date of eggs in the second generation each year. Most of the larvae hatched in early Augst can complete the second generation and grow up into the third generation, but the larvae hatched in mid-late August can not do so. The annual differentiation varied with the temperature and other factors could greatly effect the population density in hibernation. The critical photoperiod required by the Pine Caterpillar is around 13.5 hrs and the critical date fell on early August in Chongqing region, Sichuan Province, so these larvae hatched before the critical date can produce the third generation or vice versa. The present paper provide some useful date and hints to forecast and manage the pest in the Yangtze River area.
A study on the testing conditions of the hyphostroma-esterase electrophoretic pattern of Beauveria bassiana (Bals.) Vuill. was conducted. The experimental results showed that the esterase electrophoretic pattern was mainly effected by five testing factors: constituentes of culture medium, amount of culture medium used, cultural peroid for hyphostroma,amount of conidia inoculated and different solutions of extracting esterase. The total numbers and shade of the colour of the esterase-bands were changed under different conditions. On the other hand, some side effect caused by EDTA was observed. Therefore, we may make a conclusion that a stable esterase electrophoretic pattern used as a classification criterion for strains of Beauveria bassiana can be obtained under the suitable conditions.
11 plus trees were selected in 1984 from canker disease regions of the natural hybrids of P. simonii × P. italica. In order to test the effects of plus selection and supply new resistant clones to disease regions as soon as possible, the differences of the plus trees' resistance to Dothiorella gregaria Sacc. were evacuated according to their pathogenic rate, pathogenic index and pathogenic velocity index in laboratory for three years by inoculating the disease on the artificially wounded bark. The results suggests that all of the plus tree are more resistible to the disease than P. pyramidalis × P. cathayana cv. 'Beijingensis', the most resistant clones of which are Liaoning No.5 and Liaoning No.11.
Under the special absorptive wavelength of lignin, the lignin contents in the solution containing lignin and mycelial are determined by ultraviolet spectrophotometry before and after the enzymer actings. The lignolytic activity of wood-rot fungi can be detected by this method. The method can also be used in the screening of lignin-degrading fungi.
The total biomass and its distribution in different organs of Tung-Oil trees were systematically studied for two years during periods when the trees bore just and produced fully their fruits. The growing potential of each organ in different phenological phases of the trees was analysed, which expounded the dialectical relation keeping a balance between vegetative growth and reproductive growth of the trees, and provided a theoretical basis on appropriate cultivative measures for promoting their high yield.
Research results on the biological cycling of the nutrient elements in forest ecosystems were summarized, in which uptaking, returning and accumulating of nutrient elements were included. The general procedure of regulating nutrient cycling were also analysed and discussed in the paper. The rate of nutrient cycling changes with the forest types and geographical distribution. Generally, hardwood forests have higher cycling rate than coniferous forests, and those in low latitude zones have higher cycling rate than those in high latitude zones. The changes of forest productivity corresponds to the changes of nutrient cycling rates. Reallocation of nutrient elements within trees is a common phenomenon, and it is an adaptive reaction of the tree to malehabitat. Moreover, coniferous forests and those in high latitude zones have higher efficiency in nutrient use.
Provenance test of cold-hardy Loblolly Pine were carried out at 4 sites in Jianghuai Area in 1983. 5-year results indicate that the growth of height and diameter of different seed sources are significant. A significant negative correlation was found between height growth and mean temperature. The best performing seed sources come from the northern and northeastern part of the natural range. 5 superior seed sources were selected for each experiment location based on their growth performance, survival and other adaptablities to the environment.
Irrigation trial was conducted in a 3-year-old poplar plantation (Populus simonii × P. pyramidalis cv. 'Opera 8277') to study the effects of irrigation on the growth of the plantation. The results reveal that the growth of poplar plantation was promoted by rational irrigation and the increments in height, DBH and volume raised by 14.7%, 14.7% and 27.2% respectively. Irrigation brought about the expansion of leaf area and as a result increased the volume increment. The annual volume increment produced by per unit leaf area is more or less stable, approximately varied from 0.00050~0.000 58 m3/m2 and it is not influenced by the quantity of supplied water.
In this paper, the effect of clone provenance, clone and sunlight condition on anthesis and quantity of strobiles was analysed. It shows that through two years' observation: the average number of male cone/per 1 year branch in full sunshine plots is about 1.7~2.3 times of those in sunlight-deficient plots and the ratio of female cone about 3~9 times. Under the same sunlight condition, the strobile number/per branch of clones which come from the Central part of distribution area is obviously less than that of the clones from South or North part. The difference for male cone number is about 40% and for female cone number is about 100%. In the year of cool and rainy March, the anthesis of the earliest flowering clones is 12~15 days earlier than the latest flowering ones. The earliest anthesis clones mainly come from South part of the distribution area but there are also some from Central even North part; The latest anthesis ones mainly from North part but there are also some from Central or South part. Lasting fine and warm weather can make the anthesis appear earlier and shorten its duration, especially for microstrobilus.
This paper presents the results of the analysis of the nutrient content of rattan shoots of two commercial species, viz, Daemonarops margaritae Hance and Calamus simplicifolius Wei. The results show that the shoots contain a lot of protein, fat, carbohydrate, eight kinds of amino acids and various nutrient elements and vitamins, which are essential nutrient substance for human being. Therefore, the shoots can be exploited as a valuable vegetable with low sugar and high protein.
Incest breeding of Trichogramma dendrolimi Matsumura was observed in oak silkworn eggs at a rate up to 100%, the same was true in eggs of Dendrolimus punctatus Walker. In those eggs, the incest breeding occured at a late stage of female pupa. Arrhenotoky happened in the culture of individual female pupa. Results indicated no any adverse effect of incest breeding in successive generations on progeny vitality and development.
A new viewpoint has been presented on the necessity of setting up plantations for production of broodgallnut to provide mother aphids of the summer or autumn emigratting gall-aphids and to settle them on the winter host (moss) to breed mass nymph aphids for raising per unit yield of the gallnut grove. In addition,the function of the broodgallnut plantation and the technical measures have also been discussed concerning how to exploit broodgallnuts for improvement of the unit production.