The assimilation of 14CO2 and the accumulation of 14C-assimilates during grain filling period of wheat treated with dry-hot-wind were determined. The results are showed as follows: 1. Under the influence of dry-hot-wind, the chlorophyll content was decreased and the capacity of 14CO2-assimilation was also reduced. Assays of carbonhydrate content indicated that destribution pattern of 14C-assimilatcs was changed, the alcohol soluble fraction was decreased while the petroleum ether soluble fraction was increased. The total 14C-assimilates accumulated in the grain was reduced to a low level. 2. The hydrolysis and export of 14C-assimilates stored in stem was enhanced and the soluble carbonhydrates in the grain transformed more repidly into insoluble from, hence the treated plants ripened earlier than the controls. 3. Injuries caused by dry-hot-wind during grain filling period did not recover even under favorable conditions subsequently.

This paper briefly describes the characteristics of high-speed, liquid chromatography and reports some examaples on application in the researches of phytochemistry. Analyses of chemical components of five species of Chinese medicinal plants were carried out on a chromatographic instrument, which was built by our institute. They are: Camptotheca acuminata Decne., Euphorbpia helioscopia L., Salvia miltionrhiza Bge., Schisandra sphenanthera Rehd. et Wils., Daphne genkwa Sieb. et Zucc. The results of separation in the column of pellicular beads packing were compared with that of small porous particles (< 10 μm)packing.

The present paper deals with the structure of the thalli and development of the reproductive systems of four species of Liagora, namely, L. pinnata Harv. and L. setchellii Yamada, both from Xisha Qundao, and L. boergesenii Yamada and fi. decs- sata Mont., both from Taiwan sheng. The development and position of their cystocarpid involucral filaments and the formation of the gametangial clusters were described. The names of sections were also discussed. It is suggested that the develop- ment and position of the involucral filaments may serve as taxonomic characteristics. The authors agree with Yamada and Chiang that the external feature and position of the gametangial clusters of L. pinnata are easily distinguished from those of the other. We consider the present names of the section (Farinosae, Validae, Mucosae) are inadequate.

This paper records some plant impressions from the Wulidui formation of the Wucheng basin in Tongbai Xian, Henan. The xerophytic Palibinia and small leaves of various kinds of the leguminous plants are predominant. One new species, Grevillea densifolia is described. Based upon the feature of this florule, the geological age is assigned to late Eocene. The xerophilous nature of these plants indicates that during that time the Wucheng basin was a dry and hot region. The discovery of these plant fossils, there fore, has some significance in geological, botanical and palaeoclimatological researches.

From May 1976 to July 1977, we made a series of investigations on the sporo- carps and cultured young sporophytcs of Azolla imbricata (Roxb.) Nakai. It is a green manure for higher yield of rice. But we know, that the means of cultivation of this plant is restricted to the vegetative reproduction. In most cases, Azolla withers in the very hot days in summer and bitterly cold days in winter. Out preliminary investigation indicates that the sporocarps can resist the unfavorable environment such as high temperature in summer and low temperature in winter. Young sporophytes have high plasticity. Therefore, it is of practical use to adopt sporocarps and young sporophytes as a means to overcome the unfavorable environment is of practical value. The appearance of its sporocarps in nature and the cultivated process of the young sporophytes are also briefly described.

The occasionally cold current from the north often hits some regions in Southern China. It Causes a sudden fluctuation of temperature and brings chilling injury to those temperature sensitive tropical plants. The experimental results indicated that chilling temperature had a marked influence on plant metabolism of Hevea brasitiesis. With the temperature dropping below the optimum, as its period prolonged, the normal metabolism in the rubber tree was changed. The catabolism of carbo- nhydrate, nitrogen and phosphorus metabolism were all enhanced and their syntheses were inhioited particularly the toxic substances, e.g. ammonia, was accumulated in the plant.

This paper presents the chemical constituents of the essential oils of Thymus quinquecostatus Celak. in Shandong Sheng. By applying the following techniques: (a) fractional distillation, (b) column chromatography, (c) TIC, (d) GLC and (e) IR, 16 components have been separated and identified e.i. linalool, borneol, p-cymene, cineole, carvacrol and others. It is also found that this species in Shandong Sheng has two chemotypes: linalool-type and carracrol-type. In addition, the variations of content of major components of the oils in various months have been determined.

In seasons of tapping Styrax trees (Styrax hypoglauca Perk.), it is found that benzoin yields will increase significantly if the bark of stem base was slightly scraped and treated with a 10% Oil preparation of ethrel at 10–12 days prior to balsam cutting. The average benzoin yield for treated trees has been found 8–17 times as much as those of the controls. There are many advantages for application of ethrel, such as, convenient to use, resulting in larger amplitude of productive increment, only a slight in jury to the bark, and no changing in benzoin composition, etc. Thus, ethrel may be applied unquestionably to the purpose of benzoin production. It is also proved that ethrel can enlarge the size, increase the total number and broaden the distribution ranges of traumatic balsamic ducts. And then, it increases the benzoin yields.

1.The hybrid rices "Ai-yu No. 2" and "Nan-yu No. 2" are weakly photosensi- tive types. Under 10 hours of day-length their heading is accelerated by 18–32 days than that under natural day-length. The corresponing male-sterile and maintainer lines are insensitive or very weakly sensitive to short day-length. Their range of acceleration of heading is only 0–3 days. 2. The photoperiodic sensitivity of hybrid rice is determined mainly by their paternal line (the restorer line) to day-length. This should be taken into consideration in selecting new restorer lines. 3. The vegetative period of "Nan-yu No. 2" under the short day-length is shortened by 32 days, while its paternal and maternal lines by 10 days and 1 day respectively. Therefore, inheritance of photoperiodic sensitivity in this hybrid rice is transgressive. 4. Hybrid rices "Ai-yu No. 2" and "Nan-yu No. 2" display obvious heterosis in comparison with the restorer line IR24 and the control strain "Chen-chuai". 5. Under the natural day-length of Wuchang both hybrid rices have 17 leaves on the main stem while IR24 has 18. 6. Differentiation of young panicle in hybrid rice occurs at the age of 13–13.5 leaves. Panicle differentiation begins in the male-sterile lines later than in the maintainer lines by 2–5 days. The date of heading of the male-strile lines is later by 2–3 days. For propagation of male-sterile line or hybrid seed production, it is important to arrange carefully the sowing and transplanting times to make the flowering periods meet, since this difference of heading period between the male-sterile line and the maintainer line is not affected by photoperiodic conditions.

A method of haematoxylin staining used for revealing the heterochromatic zone of chromosomes in Vicia faba was reported. It was compared with the method of Feulgen reaction after low temperature treatment, and differenc and resemblance between them were analysed. Based upon the experimental results of this report and the data from of others authors work, the authors suggest that certain transitional degrees between the typical heterochromatic and euchromatic zones should be present. The heterochromatic zone of M-chromosome in Vicia faba was then divided primarily into 5 degrees and the nature of them was discussed.

The vegetation and the permafrost are mutually affected and limited. The development and the penetrating growth of root system of plants are limited by low temperature of the permafrost. The homogeneity of vegetation distribution is destroyed by forming of frost heavings, thawed lakes landslides and solifluctions. Direct sunlight is weakened by vegetation and a lot of water is depleted by transpiration, so that the surface temperature of ground is decreased. There is a thick peat layer under boggy meadow, exercising protection for the permafrost. According to the type, the structure, and the specific composition of the vegetation and the surface features of the permafrost, the distributive ranges of the permafrost can be determined. Since vegetation succession is extremely sensitive to the changes of air temperature and soil moisture, the trend of permafrost development may be speculate indirectly.

The conditions for inducing pollen embryoids and calluses and the cytological observations of androgenesis in wheat have been studied. Results are summarized as follows: 1. N6 mediumTM is apparently superior to MS medium for inducing pollen calluses. It is shown that the exogenous hormones are not necessary to initiate the androgenesis, but they can promote further growth of pollen embryoids and calluses. 2. The pathways of the androgenesis have been also investigated with the total- mount of the anther. The asymmetric and symmetric divisions in uninucleate micros- pores all can initiate embryogenesis, but the former is more frequent. 3. The micronuclei cleft from chromosome fragments, have been found both in multicellular pollen and in some albino pollen plants. It is deduced that the albino and abnormal pollen plants may originate from the multicellular pollen which contain micronuclei. 4. Both the endoduplication of the nucleus and fusion of free nuclei of pollen are believed to be the main causes for the production of the diploid and multiploid pollen plants.

Callus cultures initiated from leaves of haploid and diploid Nicotiana tabacum were transferred to a suspension culture and then treated with 0.25% EMS. Selection of nutrient mutant cells was carried out by planting the culture in a medium with 1% beef extract without any inorganic nitrogen. In this medium the normal cells turned brown and quickly died, while mutant cells remained viable and its fresh weight increased fourteen-fold after 14 days. This trait was stable as mutant cells grown at inorganic nitrogen medium without beef extract for 42 days (subcultures for 6 passages) were still adapted to beef extract medium. The relationship between various levels of beef extract (medium containing no inorganic nitrogen) and growth of normal and mutant cells was studied. Without beef extract, the normal cells were still viable but grew very slowly. The mutant cells were able to growl at 1% while stopped at 4%. It shows that some growth inhibitory factors were contained in the beef extract and the mutant cells were resisted to these growth inhibitory factors. In order to regenerate plants, mutant callus was inoculated onto a beef medium extract containing 2 mg benzyladenine and 0.5 mg NAA per liter. After one month about 10 shoots were obtained (2/3 green shoots, 1/3 albino shoots), while all other mutant calluses could not be regenerated. All the shoots could not produce any roots except those subcultured in the inorganic nitrogen medium.