Abstract:The investment in nine partical board Plants in Guangdong Province and their production were studied. Six indices, i.e. rate of proit and tax on investment, rate of profit on investment, rate of output value on fixed assets, rate of profit and tax on output value, labor productivity, and payback perlod, were applied to evaluate the economic benefit of p artical board projects in Guangdong Province. The input-output mathematical relation of nine partical board plants in Guangdong Province was regressed. After evaluation and regression, the results showed that the economic benefit of the partical board projects was not goods partical board industry belonged to erpital -intensive; the operation scale of partical board industry should not he too large; the relation between capital and output value could be positively correlrted; the relation between la' or and output value showed negative Correlation.

Abstract:The ultrastructure of the testis of the Japanese quail (Coturnix coturnix japonica) was studied under the transmission electron microscope (TEM). The spermatogonia were characterized by spherical nuclei with little heterochromatin appearing like clumps bordering the nuclear envelope; the nucleoli were distinct. The perichromatin and interchromatin granules could be clearly distinguished. The mitochondria sometimes appeared vacuolated, with short and sparse cristae, and evenly distributed in the cytoplasm.The heterochromatin of the spermatocytes was dispersed in the nuclear sap and consisted of clumps of granules, and the nucleoli were clearly discernible. The mitochondria were few in number and similar to those of the spermatogonia in distribution. This was at variance with the distribution of the mitochondria in the spermatogonia and spermatocytes of the chicken. The rough endoplasmic reticulum and Colgi complex were well-developed and the annulate lamella could be seen in the cytoplasm.The spermatids had large and round nuclei; the little heterochromatin present appeared sp-erse and granular,being located near the nuclear envelope and scattered in the nuclear sap. The electron density of the mitochondria was rather high, and the endoplasmic reticulum and Golgi complex of the cells moderately developed.The Leydig cells of the testis were irregular in shape, with distinct nucleoli. The contained considerable quantity of endoplasmic reticulum and mitochondria, both showing polar distribution. The cristae of the mitochondria were either flat and shelf-like or tubular in shape.

Abstract:The experiment in which six cropping systems was performed on a lateritic red soil were carried out from 1980 to 1984, on the campus of the South China Agricultural University, Results showed that the soil nitrogen, accumulated in all cropping systems, the ameunt of nitrogen increase in the doulle rice cropping system was low, whearas those systems includ-ing legumes, such as herbage mixed with murg bean and double cropped rice rosted with legume were the highest, the latter could increase about 150 kg/ha of nitrogen annually. Nitrogen accumulation in these systems was cue to higher efficiency of nitroyon fertilizer, and total soil nitrogen increased significantly.Phosphous balance of the soil showed deficit in all cropping systems, the effictercy of phosphorous fertilizer was low, about 1/3 of phosphorous fertilizer applied leaching to below the plow layer in most of the cropping systems.Patassium balance exhibited great deficit in the rice cropping systems. It was due to the considerable amount of K that leached tut under the sulmergeice cenditiers of rice culture the average amount reaching 44% of the potassium fertilizer applied. However, fer dryland cropping system, the potassium remained nearly in balance or showed increase, the soil potassium maintaining its original level after five years cultivation.It was demonstrated that the b(st way to maintain the N, K balance in the cropping systems was to incorporate rice straw and legume in the soil.

Abstract:The spatial distribution pattern of the adult of the striped flea-beetle, Phyllotreta striolata Fabricius, on vegetable fields were studied. The results showd that:(a)The spatial distribution of the insect pest confotmcd to negative binomial distribution and Neyman distribution.(b)The spatial pattern of the pest is an aggregative one and the basic component of distribution is the colony.(c)In the afternoon, on the Chinese cabbage and the flowering cabbage 81% of the pest concentrate on the youngest leaf and 2 leaves around it, and on the radish the greater pars of the pest concentrate on the back of the leaves.

Abstract:Based on amylose content determination done on single grain of rice, the present experiment aimed at elucidating the mode of inheritance of amylose content of rice crosses and their reciprocal including F1, F2, F3 generations. Ths results indicated that the gene dosage effect only existed in parts of the crosses and their reciprocal, in the crosses of high/low and middie/low amylose content hsren (indica) rice variety, a single major gene in association with modifying genes governed the inheritance of amylose content, high and middle amylose content was completely dominant over low amylose.

Abstract:A root rot disease of pines was found lor the first time in about ten-year-old Pinus ell-iottii stands in the Leizhou Penisula oi Guangcong l rovince of China. Field survey and inoculation tests provided convincing evidence that P p od a n en was the primary pathogen of the disease,and Botryodiplodia theobromae also a pathogen of P. e p P aeda and P.caribaea.Inoculation tests indicated that the pathogencity of D.pirea varted among different s-pecies of pines. Pinus elliottii was more susceptible to attack by D. pirea than P.taeba and P. caribaea, and that P. massoniana was resistant.The mycelia of D.pinea could survive lor more than 150 days in infected roots of P. elliottii under natural conditions, and for 120 days in natural soil of different water contents, when soil moisture was 5%, 15%, 25%, 50%,conidia could also survive for more than 120 days in natural soil. These results indicated that D.pinea was likely a soil-borne fungus.The infection of P.pinea was also related to water content, Low water content was favourable to infection by the fungus. When the water content was below 50%, D. pinea attacked lateral root section easily;wben the water content was above 50%, it was difficult for the fungus to attack. Soil moisture may also influence the occurrence and development of the disease. Lower water content lasting for 20 days could make P.elliottii seedlings more susceptible to the disease.

Abstract:本文引入模糊数间的一种距离,把类似的最小二乘法用于对模糊观测数据的分析,提出两类拟合模糊数据的模糊线性回归模型,证明确定模型的条件,给出计算模型参数的简明方法。

Abstract:The fine structural aspects of Macrocametogenesis and process of fertilization in Tyzzeria parvula were studied in tissue from the small intestine of infected young domestic geese via electron microscopy.Multi-membranous vesicles were present in both the nucleoplasm and cytoplasm of young macrogametocytes.It was observed that electron translucent vacuoles appeared to be ejected from the surface of the macrogametocytes. The wall forming bodies of type 1 (WF1) came irto view before the wall forming bodies of type 2(WF2). The WF1 was osmi-ophilic, and was smaller than tne WF2.WF1 and WF2 participated respectively in formation of the outer and inner layer of the oocyst wall. Fertilization of a macrogamete by a micro-gamete occurred prior to oocyst wall formation.Both the nucleus and the flagella of the mi-crogamete penetrated into the cytoplasm of macrogamete, but only the nucleus fused with the nucleus of macrogamete.

Abstract:通过田间试验,对小白菜花叶病寄主生长动态进行了数学分析。结果表明,小白菜生长过程符合一般种群增长动态过程,逻辑斯谛曲线拟合效果很好,即使在利用四点式平均值法估计环境容纳量和线性化方法估计其它两参数的情况下,非线性决定系数多在0.99以上,仅一例为0.97。对全部6次田间试验数据拟合的植株平均叶数m与有效积温ST的关系方程为: m=18.94/[1+exp(2.0676-2.7346×10~(-3)ST)] 群体内各植株叶数的标准差Se与平均叶数m的关系方程为: In(Se)=11.7320m-0.1959m~2+18.09261n(m)-20.59071n~2(m)-30.0681 从小白菜生长时间动态方程的拟合效果来看,利用四点式平均值法估计环境容纳量后再用线性化方法来估计其它生长参数的效果,与麦夸尔特法拟合方程的效果差异很小。这表明在实验数据较完整和样本容量较大的情况下,可直接利用前一种方法进行逻辑斯谛曲线拟合。

Abstract:Dawu mountein with the second highest peak in Guangdong province, is located at the juncture of Gaozhou County and Xinyi County. This paper reports the results of a preliminary survey of the plant resources of this mountain which revealed 184 families, 629 genera and 1209 species of wild vascular plannts, including 36 families, 67 genera and 124 species of Pteridophytes, 4 families, 5 genera and 5 species of the Gymnospermae, 144 families, 557 genera and 1080 species of the Angiospermae. Among them, 40 are new to Guangdong, 14 are unique to Dawu mountain (including 7 new species), and 7 are precious, rare and endangered species protected by national act. It is that authorities concerned promptly take m-easures to establish a natural reserve.

Abstract:In diseased plants of mulberry trees with slight symptom of wilt, we found that the pathogenic bacteria (Pseudomonas Solanacearum) Parasitized not only the vessels of the diseased root,but also the xylem parenchyma cells. Abnormal parenchyma containing large amount of pathogenic bacteria was also observed for the first time. In the stem vessel system, no pathogenic bacteria were found; most of the vessels, however, contained tyloses.

Abstract:本研究于1985～1988年,用~(60)Coγ射线诱发重瓣叶子花突变,选育新的花色品种。试验结果表明,辐照剂量为3KR和3.5KR处理的发根插条,在VM_1代均获得不同花色突变株,其中3 KR处理的出现一株分别有鲜红和橙黄色的变异,突变率为0.74％;3.5KR处理的出现两株分别为橙黄色和红黄嵌合花色变异,突变率为1.64％。通过无性繁植,已从VM_1代突变株分离纯化出两个花色各具特点的突变系,分别编号为“85-1”和“85-2”。经继代繁殖到VM_3代,表现性状稳定,花期特长,花色艳丽,具有较好的观赏价值,目前正在加速繁育推广应用。

Abstract:In this paper the site factors influencing the growth of Acacia aurlculiformis were screened on the basis of the data collected at sample lots in different areas of Guangdong province by the method of step regression. These site factors were divided into three site type groups and each group subdivided into four site types by fuzzy classification and they evaluated. Results show that site types No. 1,2,5,6,7,9,10 were good for its planting. Types No. 3 and4 were seriously deficient in potassium. Types No. 8 and 11 needed more intensive planting. type No. 12 was not suitable for planting Acacia auriculiformis.