摘要:

AbstractNutrient requirements of callus tissues previously obtained fromVigna sinensishypocotyl segments were investigated on modified White's (Miller and Skoog) and Murashige and Skoog's media containing 1 mg/1 of each of 2,4‐D and kinetin, 2% sucrose and 1% agar. Yields of tissues on the latter medium were 3 times more than the former. After studying various organic and inorganic nutrients, two synthetic media have been developed for callus cultures. The above modified White's medium further supplemented with 2% sucrose, and 500 mg/1 of urea or asparagine was suitable for a compact callus with a dry‐to‐fresh‐weight ratio around 8% and on this the tissues grew 15‐ to 17‐fold in 5 weeks. Similarly the Murashige and Skoog's medium further enriched with 2% sucrose, 400 mg/1 of urea or a mixture of aspartic acid (750 mg/1), glutamic acid (250 mg/1), asparagine (250 mg/1) and arginine (250 mg/1), was apt for a friable callus with a dry to fresh weight ratio of 3 to 4% and it promoted a 45‐ to 50‐fold increase in gr

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1974.tb03717.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

AbstractExamination of the effect of CO2‐concentration and time of day on the content of malic acid, citric acid, aconitic acid, isocitric acid, succinic acid and fumaric acid in tomato leaves, revealed that the total content of these acids will rise with the CO2‐concentration up to 0.10 vol% CO2. In the morning up to 0.22 vol% CO2was needed for optimal effect.Samples of leaves picked at 1 a.m. showed the lowest content of these acids. At 9 a.m. the content had increased, and at 4 p.m. the increase was considerable. The content of malic and citric acid constituted 36 and 34% of the total acid content. In the afternoon and the night the aconitic acid represented 14% and in the morning 20% of the total acid content. Isocitric acid, fumaric acid and succinic acid occurred only in relatively small concentrati

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1974.tb03718.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

AbstractAgrostis palustristurfs cut weekly at 1.3 cm were subjected to successive four‐week periods with day‐night temperature regimes of 20–10, 25–15, 30–20, 35–25 and 40–30°C. Plants grown at 40–30°C exhibited a growth character distinctly different from those grown at 20–10°C. They were more upright and bristle‐like in growth habit. The percentage dry weight of leaf blade tissue increased 67% and weight per unit area increased 53% between 20–10 and 40–30°C. Reduced leaf blade width was noted first at 30–20°C while leaf blade length reduction first occurred at 35–25°C. Weekly yields were significantly reduced at the supraoptimal temperature regimes of 35–25 and 40–30°C. Chlorophyll content was lowest at 20–10 and 40–30°C, the lowest and highest temperature regimes studied. Shoot density appeared to decrease under the 35–25°C regime, but no dead plants were observed. The apparent decrease in shoot density was attributed to the upright growth habit. Density decreased at 40–30°C upon death of individual plants. A community of grass plants maintained as a turf was found to change

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1974.tb03719.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

AbstractAgrostis palustrissods were grown sequentially in a controlled environment chamber at 20–10, 25–15, 30–20, 35–25, and 40–30°C day‐night temperature regimes. Leaves grown at 40–30°C contained 53% more ethanol soluble and 51% more water soluble carbohydrate than those grown at the 4 lower temperature regimes. The increase in ethanol and water soluble carbohydrate in leaves at 40–30°C could not be attributed to a blockage in translocation of photoassimilate to lower plants parts based on quantitative carbohydrate analyses on stem and stolon tissue.Manometric measurements of photosynthesis indicated that leaf blades grown at the five temperature regimes exhibited different rate capabilities when tested under non‐limiting light and carbon dioxide levels. Oxygen evolution increased directly with temperature from 20 to 40°C and was 8 to 11 fold greater than the rate of carbon dioxide evolution. Both quantitative and qualitative differences in the photosynthetic rate were postulated in the leaf blade tissue tested. The quantitative difference was attributed to a possible difference in the number of cells per unit area and their size. The qualitative difference was attributed to greater thermal stability of leaf proteins when plants were grown at supraoptimal temperatures.Manometric respiratory rate studies did not indicate similar differences in temperature response in leaf blade tissue grown at the five temperature regimes. The cause of decreased shoot growth at supraoptimal temperatures could not be attributed to decreased and limiting C‐6

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1974.tb03720.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

AbstractThe ATP pool of growing fungal mycelia, particularlyFomes annosus, has been determined. The ATP level varied during the different growth phases and correlated with the variations in the economic coefficient. Common uncouplers (at concentrations similar to those used in mitochondrial tests) decreased the ATP pool very rapidly. The size of the pool often fell 50–80% before the O2uptake decreased below that of the control and was accompanied by an increasing exudation of inorganic phosphate. Phenolic compounds added to the medium stimulated the lacease activity, generally in combination with a decrease in the ATP leve

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1974.tb03721.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

AbstractLipid composition of whole roots of wheat (Triticum vulgareVill. cv. Svenno Spring Wheat) and oat (Avena sativaL. cv. Brighton) and of cell wall fractions, mitochondrial fractions and microsomal fractions of these roots were studied. Lipid composition depended upon the level of mineral nutrition. In wheat total phospholipids, phosphatidyl choline and sulfolipid content was highest in the roots grown at the higher salt concentration, while the reverse was true for oat roots. In both species glycolipid and sterol content was lower in the high salt roots, at the same time as higher proportions of them were built into the microsomal fraction. Phosphatidyl choline content of the wheat root membrane fractions increased with the salt level, while the opposite occurred in the oat roots.The phosphatidyl choline content may be correlated with the (Ca2+, Mg2+)‐stimulated ATPase activit

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1974.tb03722.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

AbstractIntact, 14‐day‐old nitrogen‐depleted wheat (Triticum vulgarecv. Blueboy) seedlings were exposed to solutions of 0.5 mMKNO2, 0.05 mMCaSO4and 1 mMsodium 2‐[N‐morpholino]‐ethanesulfonate, pH 6.1. Nitrite uptake was determined from depletion of the ambient solution or from incorporation of15N in the tissue. An initial nitrite uptake shoulder was followed by a relatively slow uptake rate which subsequently increased to a substantially greater rate. This accelerated phase was maintained through 24 h. Nitrite accumulated to a slight extent in the root tissues during the first few hours but declined to low values when the accelerated rate was fully developed, indicating an increase in nitrite reductase activity paralleling the increase in nitrite uptake capacity. About 50% of the nitrogen absorbed as nitrite was translocated to the shoots by 9–12 h.Development of the accelerated nitrite uptake rate was restricted in excised roots, in intact plants kept in darkness, by 400 μg puromycin ml−1and by 1 mML‐ethionine. When puromycin and L‐ethionine were added after the accelerated phase had been initiated, their effects were not as detrimental as when they were added at first exposure to KNO2. The two inhibitors restricted translocation more than uptake. The data indicate an involvement of protein synthesis and a requirement for movement of a substance from shoots to roots for maximal development of the accelerated nitrite uptake phase. A requirement for protein synthesis in the transport of soluble organic nitrogen from roots to shoo

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1974.tb03723.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

AbstractMorphogenesis has been induced in excised organs and callus tissue cultures obtained from various parts of the seedling and mature plants of pimpernel (Anagallis arvensis). Vigorously growing cell cultures capable of being periodically subcultured have been established in liquid as well as on the agar‐solidified Murashige and Skoog's medium supplemented with 2,4‐D (0.1 mg/1) + kinetin (0.1 mg/l) + coconut milk (10%). The callus tissue obtained from excised hypocotyl segments is white, soft, friable and fast growing, and has been subcultured over a period of two years without showing any sign of decline in growth. The optimum conditions for growth are at pH 5.9, temperature 27°C, and with 4% sucrose as the carbon source. Under appropriate nutritional supply these cultures can be manipulated to induce rhizogenesis in the suspension cultures, and buds and “embryo‐like” structures on agar‐solidified media.The excised leaves, hypocotyl and stem segments regenerate buds. Of the cytokinins used, 6‐(y,y‐dimethylallylamino)‐purine proved to be the best for the number of cultures producing buds, as well as for the number of buds per culture. Anatomical studies revealed that buds arise from the epidermal and subepidermal layers of leaves and hypocotyl; these buds form shoots which eventually deve

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1974.tb03724.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

AbstractThe effect of exogenously supplied NAA and BA on the shoot and root formation in isolated petiole segments ofBegonia×cheimanthawas determinedin vitroon a modified White medium at a constant temperature of 24°C. The best development of normally appearing plants was obtained on media containing 0.01 mg × 1−1of NAA and 0.5 to 1.0 mg × 1−1of BA. Lower concentrations of BA yielded no shoots, higher concentrations promoted shoot formation, but the shoots were abnormal with malformed leaves. Lower concentrations of NAA resulted in poorer survival rate and no roots, with higher concentrations of NAA many roots developed, but these were thickened and their longitudinal growth inhibited. Temperature proved to be of utmost importance for the induction of shoot formation. Thus significantly fewer shoots were formed at the higher temperature (25°C) than at lower temperatures (15 to 20°C). Temperature immediately after initial transfer was of greatest importance: 25°C, during the first week followed by low temperature, produced very

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1974.tb03725.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

AbstractThe mechanism of ABA‐induced callus formation was studied in sterile bud cultures of Citrus [Citrus sinensis(L.) Osbeck] on defined media. ABA was found to promote callus formation in the abscission zone between the petiole and the branch while inhibiting bud growth. The promoting effect of ABA was dependent on the physiological state of the shoot from which buds were excised, and on the size of the explant. Callus formation was highest in autumn and summer (i.e.younger) buds, and lowest in older buds excised from previous summer flush.GA was only slightly active in promoting callus formation when applied separately, but showed a highly synergistic effect when applied with ABA: maximal callus formation was attained at a combination of 10−5MABA and 10−6MGA in the medium. Subcultures of ABA‐induced callus revealed that ABA inhibited the growth of isolated subcultured callus, while IAA and kinetin, and especially GA, promoted its rapid proliferation. A general decrease in protein synthesis was found in the abscission zone during the first 5 days of induction, while total protein content changed only slightly.The results suggest that ABA‐induced callus formation in Citrus bud explants is a multiphasic phenomenon involving, at least, two stages: (1) activation of certain cells in the abscission zone by ABA, resulting in the formation of callus layers, and (2) subsequent proliferation of the callus tissue, which is dependent on the hormonal balance in the explant. This growth‐promoting effect of ABA seems to be a general phenomenon in explants exposing a

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1974.tb03726.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY