Effect of Ethanol, Methanol and Acetone on Rooting Etiolated Cuttings of Vigna radiata in Presence of Sucrose and Auxin

Root formation on etiolated hypocotyl cuttings of Vigna radiataL. is greatly enhanced in the presence of ethanol, methanoland acctone. Low concentrations of solvents plus sucrose slightlypromoted the formation of roots. Vigna radiata, alcohol, rooting, auxin     

Ragi malt, a growth factor, for Vigna sinensis Endl. callus tissues

Callus tissue obtained from hypocotyl segments of Vigna sinensiswas capable of indefinite growth on modified White's mediumsupplemented with 1 mg/liter each of 2,4-D and kenitin, butits rate of growth was slow. Ragi (Eleucine coracana L.) maltextract obtained from the ‘IE-810’ variety promoteda 38 and 30-fold increase in the fresh and dry weights, respectively,over the controls (modified White's with 2,4-D and kinetin).Similarly 100% ‘Aruna’ ragi malt extract eliciteda nearly 40-fold increase in both the fresh and dry weights,which were as high as 21.1 g (fresh weight) and 1.64 g (dryweight) over the controls (0.48 for fresh and 0.04 g for dryweight). Growth values of 183 and 163, in respect to the freshand dry weights were obtained in a period of 5 weeks. Analysis of ‘Aruna’ ragi malt extract showed thepresence of 17 amino acids. Totally 72% (Sugars 30, myo-inositol10, amino acids 20 and inorganic fractions 12) of the growthpromoting activity of ragi malt extract was accounted for. Ragimalt extract also exhibited cytokinin-like activity when assayedwith Vigna callus which has an absolute requirement for a cytokininand auxin. ¹This work is a part of the dissertation of K. B. S. MurthyReddy in fulfilment of the requirements for the degree of Doctorof Philosophy in Botany at the University of Mysore. (Received March 28, 1973; )     

Source-sink Relationships, Seed Sucrose Levels and Seed Growth Rates in Soybean

Field experiments using two soybean (Glycine max L. Merrill)cultivars (‘Elgin 87’ and ‘Essex’) wereconducted for 2 years near Lexington, KY, USA to evaluate theeffect of source-sink alterations on seed carbohydrate statusand growth. Sucrose concentrations in developing cotyledonsof control plants were consistently low (<50 m M) early inseed development, but they increased to 100–150 m M byphysiological maturity. The concentrations increased in bothyears by 47 to 59% when 90% of the pods were removed from ‘Elgin87’, but the increase had no effect on individual seedgrowth rate (SGR). Shading (80%) reduced cotyledon sucrose levelsand SGR in both years. The critical cotyledon sucrose concentration(the concentration providing 80% of the maximum cotyledon growthrate) was estimated fromin vitro cotyledon growth at sucroseconcentrations of 0–200 m M. These critical concentrationsvaried from 72–124 m M;in planta control cotyledon sucroseconcentrations were below this critical level during the firsthalf of seed growth but exceeded it in the later stages of growthin all experiments. The estimated critical concentration wasconsistent with the failure of in planta SGR to respond to anincrease in assimilate supply and with the reduction in SGRassociated with a decrease in assimilate supply. The resultssuggest that soybean SGR is generally sink limited if photosynthesisincreases during seed filling, but source limited if photosynthesisis reduced. Copyright 2001 Annals of Botany Company Glycine max(L.) Merrill, soybean, source-sink ratios, sucrose, starch, depodding, shade, in vitro culture     

Growth Substance Interactions during Uptake by Coleoptile Segments of Avena sativa and Hypocoty1 Segments of Phaseolus radiatus

Further studies have been made on the interactions of plant-growthregulators during uptake by Avena sativa coleoptile and Phaseolusradiatus hypocotyl segments. 2, 4-Dichlorophenoxyacetic acid(2, 4-D) had no effect on the uptake of either indol-3yl-aceticacid (IAA) or -naphthylacetic acid (NAA) by Avena. On the otherhand, a-(i-naphthylmethylthio)-propionic acid (NMSP) stronglyinhibited IAA uptake non-competitively but was much less effectiveon NAA uptake by Avena. The ‘metabolic’ uptake ofIAA by hypocotyl segments of Phaseolus radiatus was very stronglyinhibited by 2, 3, 5-tri-iodobenzoic acid (TIBA).     

Factors Affecting the Abscission of Reproductive Organs in Yellow Lupins (Lupinus luteus L.): III. ENDOGENOUS GROWTH SUBSTANCES IN VIRUS-INFECTED AND HEALTHY PLANTS AND THEIR EFFECT ON ABSCISSION

Extracts of small and mature-size lupin pods yielded four substancesaffecting the growth of wheat-coleoptile sections: one acidpromotor (A), two acid inhibitors(B and X), and one neutralinhibitor(Y). Inhibitor B was extremely active, however, coleoptile sectionsshowed no signs of toxic effects; they resumed growth at a rapidrate after rinsing them and adding ß-indolylaceticand (IAA) to the medium. 1 µg of IAA was required to counteractthe effect of ‘B’ extracted from 230 mg. Of tissue.On an equal fresh weight basis the inhibiting action of ‘B’in lupin pods was 500–1,500 times more potent than thatof ‘inhibitor ß’ in etiolated pea seedlings. Small pods of plants infected with pea-mosaic virus yielded3 times the amount of ‘A’ of healthy plants (equivalentto 1 µg. IAA 0.3 µg. IAA per 25 g. of tissue respectively),and approximately the amount of ‘B’. Mature podsof virus-infected plants again yielded more‘A’,but also 2? times more ‘B’ than pods of healthyplants. Healthy pods yielded more ‘A’ than virus-infectedpods, and there was no difference in ‘X’. A lupin abscission test was developed and the effects of proximaland distal application of -naphthyl acetic acid (NAA) are presented,and discussed with respect to results of other abscission tests. ‘A’ accelerated abscission when applied proximally,and delayed or prevented it when applied distally. ‘B’strongly accelerated abscission when applied in either way.A possible mechanism explaining the abscission-inducing effectof developing pods on later flowers is discussed in terms ofthe substances ‘A’ and ‘B’. The partlyprevented abscission observed on virus-infected plants was foundto agree well with the proposed mechanism.     

Pyrimidine Nucleotide Biosynthesis in Vinca rosea Cells: Changes in the Activity of the de novo and Salvage Pathways during Growth in a Suspension Culture

Marked changes in the activity of the ‘de novo’and ‘salvage’ pathways of pyrimidine biosynthesisduring growth of Vinca rosea cells in a batch suspension culturewere observed. The activity of these pathways was investigated by determiningthe contribution of ¹⁴C of [2-¹⁴Cluracil, 12-¹⁴Cluridine. and[6-¹⁴Clorotate to the cell constituents and by measuring theactivity of the several enzymes of these pathways. During the lag phase of the culture, ‘uracil-’ and‘uridine-salvage’ pathways made the predominantcontribution to nucleotide biosynthesis, but, following theinitiation of cell division, the ‘de novo’ pathwayfor nucleotide biosynthesis operated appreciably. These results suggest that nucleotide synthesis during cellgrowth in a suspension culture can be divided into two stages:a ‘turnover stage’, during the lag phase of cellgrowth, and a ‘true biosynthetic stage’, which isinitiated in the cell division phase.     

Cultivar Differences in the Performance of Bean Seedlings at Suboptimal Temperatures

Growth analysis of plants raised under controlled environments(10–5, 12, 15, 18 and 20 °C, and 21 h photoperiod)was used to examine whether varietal differences in the minimumgermination temperature of four bean cultivars persist duringgrowth at suboptimal temperatures. A method to estimate theminimum vegetative growth temperature, based on axis relativegrowth rate, was developed. In order to compensate for ontogeneticdrift, the harvests were conducted at the same stage of developmentof the plants. Axis relative growth rates, reduction rates ofthe cotyledons and other growth parameters were calculated inorder to compare the cultivars. Cultivar ‘Marschall’showed better growth potential at 12 °C than the others,‘Pergousa‘ at 15 °C, and ‘Marschall’,‘Olsok’ and ‘Pergousa’ at 18 and 20°C. The effect of temperature on axis RGR was similar for‘Marschall’, ‘Olsok’ and ‘Pergousa’(Q₁₀ = 2·1) and more pronounced than for ‘Processor’(Q₁₀ = 1·3). Although there were significant differencesin the growth parameters among the cultivars within each temperatureused, the differences did not correspond with the differencesduring germination at low temperatures. The minimum vegetativegrowth temperature was close to 10 °C for all the cultivarstested. Phaseolus vulgaris L., beans, suboptimum temperature, growth analysis, minimum germination temperature, minimum vegetative growth temperature     

Influence of Flooding on Net CO2Assimilation, Growth and Stem Anatomy of Annona Species

A series of experiments was conducted to assess net CO₂assimilationand growth responses to waterlogging of grafted and seedlingtrees in the genus Annona. Seedlings of A. glabra, A. muricataandA. squamosa L., and scions of ‘Gefner’ atemoya(A. squamosaxA. cherimola Mill.), ‘49-11’ (‘Gefner’atemoyaxA. reticulata L.), ‘4-5’ (‘Priestley’atemoyaxA. reticulata), A. reticulata grafted onto either A.glabra, A. reticulata orA. squamosa rootstocks were floodedfor up to 60 d. Soil anaerobiosis occurred on the third dayof flooding. Seedlings ofA. glabra and A. muricata, and thescions ‘49-11’, ‘Gefner’ atemoya, andA. reticulata grafted onto A. glabra rootstock were consideredflood tolerant based on their ability to survive and grow inflooded conditions. Scions of the normally flood-sensitive A.reticulata, ‘Gefner’ atemoya, and ‘49-11’tolerated root waterlogging when grafted onto the flood-tolerantspecies, A. glabra. In contrast, flooding of A. squamosa seedlingsand rootstocks, and A. reticulata rootstocks greatly reducedgrowth and net CO₂assimilation rates, and resulted in 20–80%tree mortality. Stem anatomical responses to long-term flooding(12 continuous months) were assessed in seedlings of A. glabraand A. muricata, and trees of ‘49-11’ grafted ontoA. glabra. Flooded trees developed hypertrophied stem lenticels,particularly in A. glabra, and enlarged xylem cells resultingin thicker stems with reduced xylem density. Flooding did notincrease air spaces in pre-existing xylem near the pith or inxylem tissue that was formed during flooding. Thus, flood tolerancedid not involve aerenchyma formation in the stem. Copyright1999 Annals of Botany Company Flood tolerance, net CO₂assimilation, photosynthesis, stem anatomy, shoot growth, anaerobiosis, Annonaceae.     

The Importance of Light Intensity for Pollen Tube Growth and Embryo Survival in Wheat x Maize Crosses

The success of Triticum aestivumxZea mays crosses, used to producewheat doubled haploids, is influenced by light intensity. Toexamine the basis for this response, pollen tube growth, embryosurvival and indicators of photosynthetic rate were measuredin two wheat cultivars (‘Karamu’ and ‘Kotuku’)crossed with maize at two irradiance levels (250 or 750 µmolm^-2s^-1, PAR). Pollen tube growth was significantly affectedby light intensity in ‘Karamu’ plants but not in‘Kotuku’ plants, despite both cultivars being pollinatedby the same maize source. The percentage of pollen tubes reachingthe cavity between the ovarian wall and integuments, or in themicropyle of ‘Karamu’ plants at high light intensity(65%) was nearly three-times greater than that at low lightintensity (22%). Thus, either low light intensity can affectthe maternal wheat plant in a way that inhibits pollen tubegrowth and/or high light intensity may promote pollen tube growthin ‘Karamu’ plants. Significant differences in ratesof electron transport in plants grown at the two light intensitiesindicated that the rate of photosynthesis may also have an effecton pollen tube growth. These results have importance for improvingthe efficiency of wheat x maize crosses and other wide cerealcrosses. Copyright 2001 Annals of Botany Company Intergeneric hybridization, light intensity, pollen tube growth, embryo survival, Triticum aestivum, wheat,Zea mays , maize     

The Growth and Carbon Economy of Selection Lines of Lolium perenne cv. S23 with Differing Rates of Dark Respiration: 1. Grown as Simulated Swards During a Regrowth Period

Simulated swards of each of two selection lines of Lolium perennecv. S23 with ‘fast’ and ‘slow’ ratesof ‘mature tissue’ respiration were establishedin growth rooms at 20/15 °C day/night temperatures and studiedover four successive regrowth periods of 46, 30, 26 and 53 daysduration. The ‘slow’ line outyielded the ‘fast’,both in harvestable shoot (above a 5 cm cut) and in root andstubble. Its advantage increased over successive regrowth periodsto 23 per cent (total biomass). Gas analysis measurements onthe entire communities (including roots), during the final regrowthperiod, showed that the ‘slow’ line had a 22–34per cent lower rate of dark respiration per unit dry weight.This enabled it to maintain its greater mass of tissue for thesame cost in terms of CO₂ efflux per unit ground area. Halfthe extra dry weight produced by the ‘slow’ line,relative to the ‘fast’, could be attributed to itsmore economic use of carbon. The rest could be traced to a 25per cent greater tiller number which enabled the ‘slow’line to expand leaf area faster (though not at a greater rateper tiller), intercept more light and fix more carbon, earlyin the regrowth period. Lolium perenne L., ryegrass, respiration, maintenance respiration, tiller production, simulated swards, canopy photosynthesis, carbon economy     

Movement of Nutrients in Radiata Pine Needles in Relation to the Growth of Shoots

The pattern of needle growth and the movement of mineral nutrients(nitrogen, phosphorus, potassium and calcium) in needles ofradiata pine (Pinus radiata D. Don) were studied from needleinitiation to 2 years of age. During this period, very prominentcyclic patterns of nutrient accumulation, retranslocation andreplenishment were observed for nitrogen, phosphorus and potassium,which highlighted the potential role of needles as a nutrientreserve for growth. Significant retranslocation occurred from very young needlesabout 3 months after initiation. The phases of retranslocationcoincided with new flushes of shoot growth, and the growth ofnew shoots on a branch resulted in nutrient withdrawal frompre-existing needles, regardless of needle age and season. Suchwithdrawal occurred even in fertilized and irrigated trees onhigh quality sites and under environmental conditions conducivefor nutrient uptake. At all times, except for the short periodafter initiation when needles were actively growing, the nutrientsin the needle were readily available for retranslocation. Contraryto the general view, retranslocation of nutrients was not necessarilyrelated to senescence and ageing of needles. Because new shoots are the primary ‘sinks’ for retranslocatednutrients, an ongoing competition between different parts ofa branch for internal nutrients can be envisaged, preferencebeing for the youngest shoot in the hierarchy. The relevanceof these results to our understanding of ‘optimum nutrition’of pine trees is discussed. Pinus radiata D. Don, radiata pine, mineral nutrition, retranslocation, phosphorus, nitrogen, shoot growth     

Influence of Irradiated Pollen on Embryo and Endosperm Development in Kiwifruit

Development of seeds following pollination with irradiated pollenwas studied inActinidia deliciosa(kiwifruit) ‘Hayward’.Pollinations were carried out using two different sources ofpollen (‘Tomuri’ and ‘Matua’) irradiatedwith gamma rays at doses of 700 and 900 Gy. Non-irradiated crosseswere used as controls. Pollen irradiation had little effectonin vitropollen germination. Irradiated pollen affected seedset and seed content, and induced the formation of parthenogeneticembryos. In comparison to the control, the embryo growth ratewas slower and the endosperm contained very low amounts of storageproducts. Seed set was significantly reduced following bothdoses of irradiation. Two types of seeds were observed: (1)seeds with endosperm only; and (2) seeds with both embryo andendosperm. The proportion of seeds containing endosperm onlywas almost ten-fold higher than those containing both embryoand endosperm. Embryo production by gamma-irradiated pollenwas genotype- and dose-dependent. The induction of parthenogenesiswas higher following gamma ray doses of 900 Gy than 700 Gy,which suggests the ‘Hertwig Effect’; the best efficiencywas obtained with ‘Tomuri’ pollen. Ploidy levelof parthenogenetic embryos was evaluated by nuclear size (area)with the use of image analysis. There was a large differencein embryo nuclei size between control and parthenogenetic embryos(mean size 90.8 and 49.1 µm², respectively). It is concludedthat parthenogenetic embryos represent trihaploids.Copyright1998 Annals of Botany Company. Actinidia deliciosa, kiwifruit, pollen irradiation, induced parthenogenesis.     

Relative Sensitivity and Tolerance of some Gladiolus Cultivars to Sulphur Dioxide

Five Gladiolus cultivars, namely ‘Aldebaran’, ‘BrightEye’, ‘Illusion’, ‘Manisha’ and‘Manmohan’, were exposed to 1 and 2 µg l^–1sulphur dioxide to test their relative-sensitivity toleranceto the pollutant Plants were fumigated experimentally for 2h daily Foliar injury symptoms were observed first in ‘Manisha’followed by ‘Aldebaran’ and ‘Illusion’at the higher dose Photosynthetic pigments and leaf extractpH were significantly decreased, particularly in ‘Manisha’and ‘Illusion’ Overall disturbances in the plantmetabolism due to SO₂ treatment led to retarded growth of plants,as evident from decreased shoot length and phytomass valuesThe order of sensitivity of the five Gladiolus cultivars toSO₂ was as follows, with the greatest first Manisha, Illusion,Aldebaran, Bright Eye, Manmohan Cultivars, Gladiolus, sensitivity, sulphur dioxide, tolerance     

Effects of Some Amino Acid Analogues on the Uptake and Transport of K+ and Ca2+ in Wheat and Mung Bean Seedlings: I. CORTICAL CELL FLUXES AND TRANSPORT TO THE STELE IN EXCISED ROOT SEGMENTS, AS AFFECTED BY p-FLUOROPHENYLALANINE

Effluxes of K⁺ and Ca²⁺ from root segments of both wheat, Triticunaestivum L. cv. Capelle and mung bean, Vigna radiata (L.) Wilczek,were measured in the presence or absence of 20 mol m^–3para-fluorophenylalanine (p-FPA). The results were used to estimatethe compartment contents and transmembrane K⁺ and Ca²⁺ fluxesin root cortex cells. Using the Ussing-Teorell flux equationas the criterion, it was concluded that entry of K⁺ from theoutside solution to the cytoplasm, and from the cytoplasm tothe vacuole were active in both wheat and mung bean. Also, inboth species, Ca²⁺ entered the cytoplasm passively across theplasmalemma and was actively pumped back to the external solution.However, interpretation of the direction of active transportacross the tonoplast depends upon an assumption about Ca²⁺ activityin the cytoplasm. The only qualitative effect of p-FPA was to alter the drivingforce for K⁺ influx, across the plasmalemma in wheat, from anactive to a passive one. Quantitative effects of the analoguewere seen for K⁺ fluxes in both wheat and mung bean and forCa²⁺ fluxes in wheat. The p-FPA reduced transport of K⁺ in bothspecies, while transport of Ca²⁺ was unaffected. The implicationsof these results for the ‘two pump hypothesis’ arediscussed. Key words: Triticum aestivum, Vigna radiata, Two pump hypothesis     

Callus Induction from Mesophyll and Hypocotyl Protoplasts of Mungbean (Vigna radiata (L))

Mesophyll and hypocotyl protoplasts were isolated from Vignaradiata using a combination of Cellulase Onozuka RIO (1%) andMacerozyme (0·2%). On a modified V-47 medium, 60% ofthe cultured protoplasts divided and developed into colonies.Protoclones differentiated roots on MS medium supplemented withdifferent auxins and cytokinins; however, shoot differentiationwas not obtained. Co-cultivation of protoplasts with wild andshooter mutants of Agrobacterium tumefaciens did not lead todifferentiation of plantlets. Lysopine and nopaline dehydrogenasewere not detected in any of the selected protoclones. Vigna radiata, Mungbean, Agrobacterium tumefaciens, co-cultivation, protoplasts     

In Vitro Responses of Brassica Juncea and Vigna radiata to the Antibiotic Kanamycin

Growth responses of Brassica juncea and Vigna radiata were studiedin vitro in the presence of the antibiotic kanamycin. The dataindicate that the kanamycin concentration for the inhibitionof growth varied considerably in both the species as well asin different explants of the same species. Brassica juncea, mustard, kanamycin, Vigna radiata, mung bean     

The Growth and Carbon Economy of Selection Lines of Lolium perenne cv. S23 with Differing Rates of Dark Respiration: 2. Grown as Young Plants from Seed

Young plants of two selection lines of Lolium perenne cv. S23with ‘fast’ and ‘slow’ rates of ‘maturetissue’ respiration were individually grown from seed,together with plants of S23, their common parent, in 9.2 cmpots in a controlled environment at 20/15 °C day/night temperatures. No significant differences were found between the genotypesin leaf extension and tiller production during this early stageof their growth. They did differ however, by an average of 26%,in the rate of dark respiration of fully expanded leaf laminae.The use of a simple model demonstrated that such a differencein respiration could alone account for the different rates ofdry matter production shown by the selection lines when grownas young crops from seed. Possible penalties of ‘slow’respiration are also considered. Lolium perenne L., ryegrass, respiration, maintenance respiration, stimulated swards, leaf growth, tiller production, carbon economy     

CORRECTIONS, VOLUME 29

Part 1, under the frontispiece portrait of Dr. N. B. Eales,the words ‘President 1948–1951’ should havebeen added. Page 103, line 49, for ‘Newton Collection’ read‘Norman Collection (Canon Norman)’. 185, line 37, for ‘capillaris’ read ‘capillacca’. 188, Table 1, for ‘bemoralis’. read ‘nemoralis’. 188, Table 2, for ‘Cochlicella acuta (Müll)? ventrosa(Fér.)’ read ‘Cochlicella ventrosa (Fér.)’. 191, line 24, for ‘araheo-’ read ‘archeo-’.     

Tree Suppression and the Self-thinning Rule in a Monoculture of Pinus radiata D. Don

An experiment comparing different initial planting densitiesof Pinus radiata D. Don was established in 1940 at Mt. Burrin south-east South Australia. It had been measured periodicallyto age 40 years. It is shown that after some years the treesof each individual plot of the experiment segregated into agroup of ‘suppressed’ trees which grew little indiameter and a group of actively growing ‘dominant’trees. This is consistent with other work that has suggestedthat monocultures tend to produce a two-tiered canopy. The slopeof the relationship between the logarithm of the mean weightper tree and the logarithm of the density of the various plotsof the experiment (the ‘competition-density effect’)was computed at each age at which the experiment was measured,both for all live trees of the plots and for the dominants only.For this analysis tree weights were estimated using the allometricrelationship between weight and diameter at breast height. Forthe dominants, the slope rapidly declined with age until itapproached – 1.5, which is the limiting slope of the competition-densityeffect or the so-called ‘self-thinning rule’. Whenall live trees of the plots were used, the slope declined slowlywith age but remained far from – 1.5. Previously, theself-thinning rule has been seen as determining the way in whichmortality, i.e. self-thinning, occurs in stands. In the presentwork, the rule is found to apply to the larger, actively growingtrees of the stands soon after they start to suppress the smallertrees and long before substantial mortality has occurred inmany stands. Thus tree suppression, rather than mortality, isseen to determine the rule. The pattern of diameter growth oftrees of the various stands of the experiment is found to beconsistent with previous findings that skewness of the frequencydistribution of diameters of trees of stands increases withtime. Pinus radiata D. Don, radiata pine, self-thinning, competition