February 1964, Volume 12 Issue 2

 

          Research Articles
A Comparative Study of Gracilaria foliifera (Forssk.) B耳rgs. and Gracilaria textorii (Suring.) De Toni
Author: C. F. Chang and B. M. Xia
Journal of Integrative Plant Biology 1964 12(2)
      
    Gracilaria foliifera (Forssk.) Borgs. was first described from the Red Sea by Forsskal in 1775 under the name Fucus foliifer Forssk., among whose synonyms, Borgesen (1932: 7) listed G. lacinulata (Vahl) Howe and G. multipartita (Clem.) J. Ag., G. textorii (Suring.) De Toni was originally described from Japan by Suringar in 1867 under the name Sphaerococcus (Rhodymenia) textorii Suring., among whose synonyms, Dawson (1944, 1949) and Ohmi (1955) listed G. vivipara S. et G., G. sinicola S. et G., G. johnstonii S. et G. and G. vivesii Howe. In China, G. foliifera has previously been reported from Peitaiho (Collins, 1919, under G. multipartita; Howe, 1924, under G. lacinulata), Tsingtao (Howe, 1934; Tseng and Li, 1935) and Chefoo (Tseng and Li, 1935). G. textorii has already been reported from Tsingtao (Tseng and Li, 1935; Tseng and Chang, 1952, 1959, 1963). The latter is a very common species in the northern Chinese marine flora. As pointed out by De Toni (1897; 449) and May (1948: 42), G. textorii has a close resemblance to G. foliifera and it is rather difficult to distinguish the two species. Although Okamura (1900) and Ohmi (1955) each gave a detailed account of G. textorii, but no one seems to have published a critical study of G. foliifera (Forssk.) Borgs. Very fortunately, some foreign specimens including a few authentic specimens from various sources deposited in the Herbarium of the Institute of Oceanology, Academia Sinica, were available for our study, thus rendering the present study possible. The writers were at first tempted to refer G. textorii as a forma of G. foliifera, but later, after a thorough study of the specimens available, we found two differences between the two related species in the structure of cystocarp. In G. foliifera, the pericarp consists of many layers of cells, of which cells of the outermost layer are pigmented and anticlinally erect, whereas those of the inner layer are colorless, connected radially and periclinally with each other by means of distinct connecting filaments with indistinct cell walls; the gonimoblast is composed of large vacuolated cells. In G. textorii, the pericarp consists of 2每3 superficial layers of anticlinally erect pigmented cells, and 6--12 inner layers of colorless, irregularly shaped, more or less loosely arranged cells with very distinct cell walls; the gonimoblast is composed of smaller vacuolated cells. After reexamination of the Chinese specimens on the basis of the above discussed characteristics, we have come to the conclusion that all of them are referable to G. textorii. The record G. foliifera should, therefore, be removed from the algal list of China. In the present paper, a discussion has been made on the geographical distribution of G. foliifera and G. textorii, on the former being an Atlantic on the latter a Pacific species. Whether both species do occur concurently in the Indian Ocean as previously reported by various algologists must be verified by reexamination of this specimens involved.
Abstract (Browse 2185)  |  Full Text PDF       
The Uptake of p32 by Different Regions of Wheat Roots
Author: T. H. Tsao, H. T. Liu and C. H. Yang
Journal of Integrative Plant Biology 1964 12(2)
      
    Although much has been done concerning the absorbing zone of the root, there is an obvious diversity of opinions among different workers. The present work is undertaken to obtain more critical data on this problem. The unbranched portions of the primary roots of 5每7 day old wheat seedlings cultured in tap water were used as experimental material. Radioactive phosphorus was used as tracer. Besides the usual radioactivity counting technique, the roots were marked with Indian ink at 1 mm intervals to ascertain the growing zone. Paraffin sections were made to observe the anatomical structures. It was hoped that by correlating physiological functions of different segments with its morphological structures, some insight may be obtained on the mode of ion absorption. The following results were obtained: 1. In nearly all experiments, the radioactivity distribution curve showed two distinct maxima. The first accumulation maximum occurred at 0每3 mm from the tip, corresponding morphologically to the growing region of the root in which the embryonic cells of the root tip were elongating. The second accumulation maximum was located at nearly 10 mm from the tip, corresponding to the region where root hairs originated. 2. The location of the first maximum showed some variation, appearing at 0每1 mm or 2每3 mm from the apex (Fig. 1 A & B). Similar phenomenon had been reported by Steward with Narcissus roots. The explanation for this variation remains to be sought. 3. The two maxima differed physiologically in the following way: 1) The first maximum appeared 2 minutes after the roots had been exposed to the solution, the second one appeared later and became more pronounced as time went on (Fig. 2). 2) 2,4-dinitrophenol inhibited the first maximum to a greater extent than it did the second one (Fig. 4). 3) After the roots were removed from the p32 solution to distilled water, the pre- accumulated p32 underwent redistribution within different sections of the root. The first maximum rose higher with time, while the second maximum lost radioactivity markedly (Fig. 3). 4) When p32 was supplied locally at the 0每3 mm, 0每10 mm or 0-30 mm sections of the root, the radioactivity counts at the first maximum of the three different treatments were very close together, while the counts at the second maximum deviated considerably. It was considered that the second maximum was of double origin, i.e., partly from the migration of p32 from the first maximum (Fig. 5) and partly from the direct absorption by that zone. The results lead to the belief that the growing region of the root (the region just behind the meristematic region) is most concerned with the initial absorption of p32.
Abstract (Browse 1852)  |  Full Text PDF       
妒戒批折快扶我快 扼志快找志抉抄 扼找忘忱我我 批 把我扼忘 i. 妖忘折忘抖抉 我 抉抗抉扶折忘扶我快 扼志快找抉志抉抄 扼找忘忱我我 批 把我扼忘
Author: 妥忘扶 妊我 -抒批忘 我妣我 圾改扶抆 -忘扶抆
Journal of Integrative Plant Biology 1964 12(2)
      
    
Abstract (Browse 1913)  |  Full Text PDF       
The Effect of L-Ascorbic Acid on the Greening of Etiolated Soybean (Glycine max Merrill) Cotyledons
Author: C.A. Mei, C.S. Fang and S. H. Yuan
Journal of Integrative Plant Biology 1964 12(2)
      
    1. The formation and accumulation of chlorophyll in cotyledons of etiolated soybean seedlings was found to be promoted by ascorbic acid treatment. 2. The increments of chlorophyll contents in soybean cotyledons by ascorbic acid treatment were different at different temperatures, and there was an optimum at 30 ⊥. 3. The absolute contents of chlorophyll in cotyledons were increased with the length of etiolated soybean seedlings. 4. The amounts of required ascorbic acid at different ages were different. Young and old seedlings were more sensitive than middle aged ones. 5. If soybean seeds were soaked in the solution of ascorbic acid before germination, there was more chlorophyll being formed and accumulated in etiolated cotyledons. 6. If the seeds were treated by ascorbic acid, the increase of chlorophyll a was greater than that of chlorophyll b, but when the seedlings were treated, the increase of chlorophyll b was greater than that of chlorophyll a. 7. During the illumination of etiolated soybean seedlings, chlorophyll a appeared first.
Abstract (Browse 1889)  |  Full Text PDF       
The CO2 Assimilation Rate of Plant Communities as a Function of Leaf Area Index
Author: Wang Tian-duo and Wei Jin
Journal of Integrative Plant Biology 1964 12(2)
      
    A light chamber was constructed for the measurement of CO2 assimilation by plant communities. The chamber was illuminated either by sunlight or by a group of incandescent lamps. The temperature of the chamber was kept constant by flowing water and adequate inside ventilation was ensured by an electric fan. To simulate field conditions, similar plants were placed outside the chamber, or, in the case of artificial illumination, the side walls of the chamber were covered with mirrors. The CO2 assimilation rate was measured by the compensation method, in which the air sample was being drawn continuously through the measuring apparatus, the change of CO2 content due to photosynthesis in the chamber was detected colorimetrically and CO2 was added from time to time to keep its concentration at 0.03%, i.e., the CO2 concentration of the atmosphere. From the amount of CO2 added in a given time, the rate of assimilation was calculated. The CO2 assimilation rate of plant communities with different leaf area indices were measured. The results obtained with wheat, rice, perilla and sunflower were shown in Figs. 1每4. The CO2 assimilation-leaf area curves are similar in general form, direct proportionality exists only at lower leaf areas, and when the leaf area increases up to a certain value, the CO2 assimilation rate gradually ceases to increase with it. The optimal leaf area, i.e., the leaf area at which the assimilation rate reaches its maximum, is about 4 with rice and wheat, 5每6 with Perilla and 2每3 with sunflower. The figures obtained with rice and wheat were in accord with those obtained by calculation based on light intensity distribution and the rate of assimilation of individual leaves as a function of light intensity. The causes of the difference between different plant species were discussed in relation to the arrangement of leaves. The maximum assimilation rates of communities of wheat and rice were about 3.5 and 4.2 g CO2/M2 land surface/hr, respectively, which are more than twice as much as those of a single layer of leaves of the same area. This shows the benefit of plant com- munities with many layers of leaves in ensuring better utilization of strong light.
Abstract (Browse 2526)  |  Full Text PDF       
Accumulation and Movement of Starch During Caryopsis Development of the Wheat
Author: S.Y. Hu
Journal of Integrative Plant Biology 1964 12(2)
      
    The temporary and permanent accumulation of starch and its movements in various parts of the caryopsis of wheat during its development has been investigated. The results are summarized as follows: 1. In the ovary wall starch deposit begins at the time of megaspore mother cell formation, and increases rapidly with the development of ovary and embryo sac. At 7- celled embryo sac stage, the starch content of the ovary wall is at a maximum, but with the further development of embryo sac, the starch content greatly declines. Soon after fertilization, the cells of ovary wall are entirely filled with a heavy starch deposit again, and the starch content is at a second maximum. As the grain matures, the starch content of ovary wall gradually diminishes in association with the collapse of greater part of the parenchymatous cells in the ovary wall. 2. The abundant starch grains are also present in the stigma during the maturation of pistil. Pending the reception of pollen grains the stigma starch deposit is thinning out. During the growth of pollen tube in the stigma tissue, the starch content further diminishes and then completely disappears throughout the entire length of the stigma. The reduction of starch in the stigma is interpretated to mean that starch is converted into soluble sugars and contributes to the nutrition of the growing pollen tubes. 3. The integument and nucellus lack starch in the entire course of seed development. 4. A marked quantity of starch is accumulated in the egg cell and zygote itself and is presumably used in the early development of the proembryo, starch grains then diminish in quantity and disappear in later proembryo. The starch deposit again appears in the differentiating embryo, but in matured embryo, disappears for a second time. Food reserves of protein bodies, not starch, are found within the mature embryo. 5. Starch grains are always present in endosperm tissue during the entire course of its development, but a large quantity of starch is accumulated only in the later stage. The rise of starch in the endosperm coincides strikingly with the decline of the heavy starch deposit in ovary wall during the caryopsis development from proembryo stage to mature grain. It is suggested that the synchronization of the depletion of starch deposit in the ovary wall and its accumulation in the endosperm tissue denotes translocation from the former tissue to the latter. The lack of starch grains in the region of endosperm around the embryo during the course of embryogenesis may be connected with the digestion and absorption for food by the maturing embryo from the adjacent tissue. In brief, there are two major phases of starch accumulation during the period from ovule primordium to mature grain. The first consists a massive temporary deposit in the ovary wall; the second culminates in a large permanent accumulation in the endosperm.
Abstract (Browse 2086)  |  Full Text PDF       
Feminization of Stamens of Alternanthera philoxeroides Grisebich
Author: Chun Cho
Journal of Integrative Plant Biology 1964 12(2)
      
    The course of the feminization of the male flower of this plant is a common phenomenon in Kianwan district of Shanghai. The plant with feminized flowers shows no changes in the morphological characteristics of the vegetative organs. The main character is that the five stamens have been displaced by five pistils. A new form of flower with six pistils has been found. The plant with fiminized flowers may develop in groups by vegetative multiplication. Its newly-formed character is permanent. Complete fiminization is seen at various places in Kianwan district. However, it possesses the morphology of various degrees of transition.
Abstract (Browse 1883)  |  Full Text PDF       
妞 志抉扭把抉扼批 抉 扭快把快忱志我忪快扶我我 攸忱快把 折快把快戒 抉找志快把扼找我攸 抗抖快找抉折扶抑抒 抉忌抉抖抉折快抗 〞改抗扼扭快把我技快扶找忘抖抆扶抑快 忘扶忘抖我戒抑 忱抖攸 把忘戒扶抉忍抖忘扼扶攸 技扶快扶我抄 抉 找抉折抗快 戒把快扶我攸 我扼抗批扼扼找志快扶扶抉忍抉 我 扭抉忱抖我扶扶抉忍抉 攸志抖快扶我攸
Author: 完忪忘扶 圾改抄 - 折改扶 我 孛戒我扶抆 尾抄 - 扼攸扶
Journal of Integrative Plant Biology 1964 12(2)
      
    
Abstract (Browse 1761)  |  Full Text PDF       
 

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