Primary Leaf Stage Research Articles

Rapid and early changes in morphology and gene expression in soya bean seedlings emerging in the presence of neighbouring weeds

SummaryLight signalling is an important mechanism of plant competition during the early stages of seedling development. Far‐red‐enriched (FR‐E) light reflected from neighbouring weeds has been shown to induce the shade avoidance response leading to changes in plant morphology and increased variability in yields. In this study, the morphological and molecular changes occurring at the hypocotyl arch and primary leaf stage of soya bean development were investigated in response to FR‐E light reflected from neighbouring weeds. A reduction in the root/shoot was identified at the hypocotyl arch stage, and an increase in height was detected at the unifoliate stage of soya bean seedlings. In addition, FR‐E light induced a change in the expression profile of reactive oxygen species (ROS)‐scavenging genes. Early in seedling development, ROS‐scavenging genes were upregulated. However, this trend was reversed at later stages of development with downregulation of several ROS‐scavenging genes. These results demonstrated the rapidity of induction of the shade avoidance response and that gene expression in soya bean seedlings was dependent upon developmental stage and tissue type sampled.

The effect of indole acetic acid on the performance of maize (<i>Zea maysl</i>.)in a Southern Guinea Savanna Zone of Nigeria

Poor soil fertility and nutrient depletion continue to present huge challenges to successful crop production in southern Guinea savanna zone of Nigeria. Consequently, a study was conducted at Ilorin - Nigeria in a southern Guinea savanna zone during the wet seasons of 2012 and 2013 to evaluate the effects of indole acetic acid (IAA), a growth regulator, on the growth and yield of maize and its economic implications. The treatments imposed were five rates of IAA (0, 200, 400, 600 and 800 ppm) using a randomized complete block design replicated three times. A basal NPK fertilizer was applied at 3WAP and IAA was applied at the primary leaf stage foliarly. Data were collected on growth parameters and grain yield of maize. Analyses of variance (ANOVA) for all observations were performed and mean separation was done by using the least significant difference (LSD). Cost benefit analysis was also determined. The result of the experiment indicated that using IAA significantly (P<0.05) increased growth and grain yield of maize from 3300 to 3957.9kgha-1 but the result of economic analysis indicated that the control produced the highest net returns (N225,130 in 2012 and N232,959.00 in 2013) and was more economical because of high cost of indole acetic acid for maize cultivation. Keywords : maize, growth regulator, growth, grain yieldand net returns.

Impact of cucumber mosaic virus infection on the varietal traits of common bean cultivars in Iran.

Cucumber mosaic virus (CMV) appears to be one of the most widespread pathogens on beans. In the present research, 49 Iranian lines and cultivars of common bean (Phaseolus vulgaris) were screened for their reaction to CMV. Plants at primary leaf stage were inoculated with CMV by rub inoculation and then they were kept in an insect-proof growth chamber at 20°C. Three weeks postinoculation, inoculated plants were assayed based on their symptoms, growth rate, fresh and dry weights and virus titer. Results of the present study showed that a line, D81083, had moderate resistance, six lines and cultivars were found to be tolerant to the CMV and 42 lines were found to be susceptible, these plants exhibited severe symptoms and accumulated high levels of virus titer. However in the present research one moderately resistant line and six tolerant lines and cultivars were identified for use in breeding and cultivation and also for future on researches bean.

Protection of melon plants against Cucumber mosaic virus infection using Pseudomonas fluorescens biofertilizer

This study was carried out to characterize a virus causing severe mosaic, yellowing, stunting and leaf deformation on melon ( Cucumis melo L.), and evaluate the capacity of Pseudomonas fluorescens as biofertilizer to improve plant growth and restrict the accumulation of the virus in the plant. The virus was identified as an isolate of Cucumber mosaic virus (CMV) by means of symptoms on indicator plants, serological characteristics using double antibody sandwich-enzyme linked immunosorbent assay (DAS-ELISA) and immunochromatography, and molecular weight of coat protein on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The source of the virus infection was also determined by the same means. P. fluorescens was used as seed treatment and soil applications. The seedling grown from bacterial treated seeds in non-treated soil and those grown from non-treated seeds in bacterial treated soil were mechanically inoculated with CMV extract at the primary leaf stage. Two proteins representing CMV coat protein appeared on 10% SDS-PAGE of 24 and 26 kD. It has been found that 9 of 35 weed plants harbor CMV. Treatment seeds and soil with P. fluorescens suspension induced significant reduction in virus accumulation in the plants as proved by absorbance values of ELISA- reactions. Minimum absorbance values of ELISA reactions at 405 nm were found to be 0.160 and 0.298 for seed and soil treatments, respectively when compared with 1.190 for samples from CMV-inoculated plants (control). The inhibition activity of P. fluorescens against CMV continued to be significant up to 20 days of virus inoculation with absorbance values of ELISA-reactions (0.460 and 0.930) for seed and soil treatment, respectively. The results indicate that P. fluorescens is able to induce systemic resistance against CMV in the plants. Key words : Cucumber mosaic virus (CMV), Cucumis melo , melon, plant growth promoting microorganisms (PGPM), Pseudomonas fluorescens , viral diseases management.

Occurrence of ascorbigen, a phytoalexin-like compound in non-stressed or uninfected cabbage in the primary leaf stage

Occurrence of ascorbigen (chemically bound L-ascorbic acid) was studied in extracts of different cultivars of cabbage in cotyledonic and primary leaf stages by thin-layer chromatography, UV-VIS spectroscopic and mass spectrometric measurements. The eventual presence of 1’-methylascorbigen was also studied. It has been shown that samples prepared from cotyledons did not contain ascorbigen, in contrast to the plants in primary leaf stage. 1’-methylascorbigen was not identified in the analysed plant samples. These results demonstrate that ascorbigen is already formed in the early (primary leaf stage) development stage of cabbage.

Reduction in aggressiveness among hybrids between host-specific pathotypes of Magnaporthe oryzae is caused by reduced ability to overcome adult resistance at the level of penetration

A genetic cross between a Triticum isolate (pathogenic on wheat) and a Setaria isolate (pathogenic on foxtail millet) of Magnaporthe oryzae yielded several F1 cultures that were virulent on both wheat and foxtail millet at the primary leaf stage. To estimate whether these cultures survive in nature, they were sprayed onto 1-, 2-, and 3-week-old wheat and foxtail millet. As the age of the inoculated plants increased, the lesion number and size were greatly reduced. The F1 cultures were almost nonpathogenic on both wheat and foxtail millet at the 3-week-old stage. Cytological analysis revealed that the low pathogenicity of the F1 cultures on older plants was primarily associated with a reduced ability to penetrate the cuticle. When placed on wounded leaf surfaces, the F1 cultures produced large lesions on 4-week-old wheat and foxtail millet. These results indicate that hybridization between species-specific pathotypes results in a reduction of aggressiveness. We therefore suggest that, even if such hybrids were produced in nature, they might not survive in the natural environment.

Growth and nocturnal acid accumulation during early ontogeny of Agave attenuata grown in nutrient solution and in vitro culture

Dry matter production of shoots and roots and the diurnal fluctuation of titratable acidity of single leaves were investigated in the CAM plant Agave attenuata during the first 70 d after germination. The plants were grown either in vermiculite sub-irrigated with a nutrient solution or in in vitro cultures on an inorganic nutrient agar. Two types of culture tube covers were used: either airtight closures or polypropylene caps with membranes permeable to air.In the earliest ontogenetic phases of development (cotyledon and primary leaf stage), the plants were already able to carry out considerable nocturnal organic acid accumulation. In vitro cultivated plants, from the beginning of their development, were also capable of diurnal acid fluctuation, though of distinctly weaker activity than the pot plants. The mean relative growth rates (RGR) of pot culture plantlets approached a third of perennial herbaceous plants. Plantlets grown in in vitro culture reached only half to the one quarter of the RGR of pot plants. The reduced yield could be attributed to the low CO2 supply in the culture tubes and the less than optimal water and nutrient supply in the agar medium.

Effect of ammonium iron (III) citrate as liquid fertilizer on wheat

Abstract Wheat (Triticum aestivum L. var. Mahhi) was grown in pots and in field plots to test the effects of ammonium ferric citrate as a fertilizer for plants grown on soils inducing Fe deficiency chlorosis. The soil used in pots was a sandy loam taken from the same plot. Two applications of liquid ammonium ferric citrate fertilizer were applied to the plants at the primary leaf stage and at the tillering stage. The fertilizer was applied as a solution eitherito the soil or,as a foliar spray at 0, 0.25, 0.5, and 0.75 mg Fe kg‐1 soil or mg L‐1 solution with a constant level of 100 mg N kg‐1 soil as NH4NO3. Plots and pots were divided into a group treated by soil amendment and into a group with a foliar spray. Control plants received no added Fe. No Fe chlorosis symptoms were found in either Fe treated foliar application or soil amendment. Nitrogen enhanced Fe uptake through root and aerial organ absorption when applied as ammonium ferric citrate solution.

Potato Leafhopper Control, 1981

Abstract The test was planted Jun 15 on the Cal Waterman farm near Batavia, NY. Each treatment consisted of two 30-ft rows bordered on each side by 2 untreated rows replicated 4 times in a Latin square design. Sidedress applications (2 inches to the side and 2 inches deep) using a hand-pushed cone seeder were made on Jun 29 (primary leaf stage) at the rate of 9.3 oz formulation/1000 ft of row. Efficacy was determined by examining 50 trifoliate leaves in each treatment ca once/wk from beginning of Jul to mid-Sep and counting the leafhopper nymphs present.

Potato Leafhopper Control, 1981

Abstract The test was planted Jun 15 on the Cal Waterman farm near Batavia, NY. Each treatment consisted of two 30-ft rows bordered on each side by 2 untreated rows replicated 4 times in a Latin square design. Sidedress applications (2 inches to the side and 2 inches deep) using a hand-pushed cone seeder were made on Jun 29 (primary leaf stage) at the rate of 9.3 oz formulation/1000 ft of row. Efficacy was determined by examining 50 trifoliate leaves in each treatment ca once/wk from beginning of Jul to mid-Sep and counting the leafhopper nymphs present.

Identification of Soybean Germplasm Lines and Cultivars with Low Incidence of Soybean Mosaic Virus Transmission through Seed1

Soybean [Glycine max (L.) Merr.] cultivars and germplasm lines from the USDA soybean germplasm collections were tested to determine the incidence of soybean mosaic virus (SMV) transmission through seeds. Eighthundred ninety‐seven accessions were used, 400 from the tropical maturity groups (VIII, IX, and X) and 497 from temperate maturity groups II and III. Field‐grown soybeans at Isabela, Puerto Rico (18° N Lat) or Urbana, 111 (41° N Lat) were manually inoculated at the primary leaf stage with the “Illinois severe” isolate of SMV (SMV‐I1‐S). Seeds harvested from SMV‐I1‐S infected plants were planted in sand benches in a greenhouse and the incidence of virus infected seedlings was determined by observation of symptoms and by indexing. In 1976, all 897 lines were tested with 200 seeds per line. In 1977, 98 tropical lines and 35 temperate lines which had low incidence of transmission in 1976 were tested with 1,000 seeds per line. Nontransmitting lines from 1977 tests and their maturity group classification were FC 31678 (III), PI 60279 (II), PI 68680 (II), PI 70019 (III), PI 70036 (II), PI 88303 (II), PI 91115 (II), PI 92684 (II), PI 92718‐2 (III), PI 203406 (VIII), PI 240664 (X), PI 325779 (IX), PI 360835 (II), ‘Arisoy’ (VIII), ‘Cloud’ (III), ‘Manchu 2204’ (III), ‘Merit’ (0), ‘Mukden’ (II), and ‘Virginia’ (IV). Most temperate lines selected for absence of seed coat mottling in 1976 had a high degree of mottling when tested in 1977.

The Effect of a Growth Retardant Compound (B4) onPhaseolusBeans

SummaryWhen the growth retardant B4 was applied to Phaseolus beans at the primary leaf stage or at one week before flowering, a temporary dwarfing effect occurred and less total vegetative growth was produced. Although these pre-flowering treatments delayed the production of peak pod numbers, no effect on final seed yield occurred. In contrast, an application of B4 during the early pod-fill stage gave a less marked reduction in vegetative tissue, but increased seed yield by 16%. It is suggested that this extra yield may have resulted from a reduction in pod shading by leaves which enabled a greater direct contribution to seed yield from pod photosynthesis. Alternatively, a restriction in growth of new leaves may have given a greater transfer of assimilate to the pods from older leaves.

Verteilung von Stickstoff auf Sproß und Wurzel bei jungen Bohnenpflanzen nach der Aufnahme von NO und NH

Translocation of nitrogen to the shoot of young bean plants after uptake of NO and NH by the rootPhaseolus vulgaris plants (var. nana, cv. Saxa) at the primary leaf stage (without nodules) were fed during 6 hours with 15NO and 15NH, respectively. 24 hours after the absorption period more 15N from the absorbed NO was translocated from the root to the shoot. The presence of NH in the nutrient solution enhanced the translocation of 15NON, probably by an inhibition of nitrate reductase. NH4‐+15N is mainly retained in the root by a high incorporation into the root protein. It can be concluded that nitrogen from newly absorbed NO is not retained and used for protein synthesis in the root according to the root's potential to synthesize protein. Nitrate reduction in the root is considered to be the limiting factor. This is supported by the fact that withdrawal of NO in the nutrient solution prior to the 15N‐experiment increased NOtranslocation to the shoot as a consequence of a lowered level of nitrate reductase. In an experiment with 14NOsupply to the roots and 15NOapplication to the primary leaves (infiltration method) a considerable amount of 15N was translocated from the leaves to the roots. This indicates that an insufficient NOreduction in the root can be substituted by a retranslocation of reduced N‐compounds from leaves to the roots. The proportion of NO reduced in the root influences also the pattern of primary distribution of nitrogen in the shoot of plants at the 4 leaf stage. At a concentration of 0,2 meq/l NO in the nutrient solution as compared to 20 meq/l NO during 10 hours a relative higher amount of 15N was transported from the root to the younger, growing leaves i.e. via the phloem to metabolic sinks.

STIMULATION OF VEGETATIVE AND REPRODUCTIVE GROWTH OF BUSH BEAN PLANTS BY NAPHTHENATES

Plants of bush bean, Phaseolus vulgaris L., were sprayed with solutions of sodium and potassium naphthenates in the concentrations 50, 100, 500, 1000, 2500, and 5000 ppm. The treatments were applied when the plants were two, three, five, and seven weeks old, and also at various combinations of these times. A single application of 5000 ppm naphthenate to two-week-old plants, and multiple applications which included treatment of plants at this primary leaf stage of growth, resulted in the greatest stimulation to juvenile growth, measured as fresh and dry weights of stems and leaves, four weeks after treatment. This treatment also resulted in the greatest increase in green pod yield (20%), seven weeks after spraying, and in ripe seed production (8%). No advantage resulted from multiple treatments in these instances.

Interactive Effects of Gibberellic Acid and Salinity on the Growth of Beans

Nieman, R. H., and Leon Bernstein. (U. S. Salinity Laboratory, Riverside, Calif.) Interactive effects of gibberellic acid and salinity on the growth of beans. Amer. Jour. Bot. 46(9): 667–670. 1959.—Dwarf red kidney bean plants, grown from the primary leaf stage to maturity on a graded salt series (0, 1.5, 3.0 and 4.5 atm. O.P. NaCl added to a base nutrient solution), showed a progressive and highly significant growth depression with increasing concentration of NaCl. At low levels of salinity (0 and 1.5 atm. O.P.), gibberellic acid applied as a spray to primary leaves, in concentrations of 10 and 100 p.p.m. in distilled water, increased the stem length, fresh and dry wt. of both the top and the root, the yield of green beans, area per leaf, and the total leaf area per plant. At high levels of salinity (3.0 and 4.5 atm. O.P.) growth was so severely suppressed that the expression of all gibberellin effects, except the increase in stem length, was essentially prevented. Gibberellin was, therefore, ineffective in overcoming the salt-induced suppression of growth. An increased rate of water use per unit leaf area was quite consistently observed with the gibberellin-treated plants. This may be simply the result of the increased exposure to light and to air movement of leaves on an elongated stem.

INTERACTIVE EFFECTS OF GIBBERELLIC ACID AND SALINITY ON THE GROWTH OF BEANS

Nieman, R. H., and Leon Bernstein. (U. S. Salinity Laboratory, Riverside, Calif.) Interactive effects of gibberellic acid and salinity on the growth of beans. Amer. Jour. Bot. 46(9): 667–670. 1959.—Dwarf red kidney bean plants, grown from the primary leaf stage to maturity on a graded salt series (0, 1.5, 3.0 and 4.5 atm. O.P. NaCl added to a base nutrient solution), showed a progressive and highly significant growth depression with increasing concentration of NaCl. At low levels of salinity (0 and 1.5 atm. O.P.), gibberellic acid applied as a spray to primary leaves, in concentrations of 10 and 100 p.p.m. in distilled water, increased the stem length, fresh and dry wt. of both the top and the root, the yield of green beans, area per leaf, and the total leaf area per plant. At high levels of salinity (3.0 and 4.5 atm. O.P.) growth was so severely suppressed that the expression of all gibberellin effects, except the increase in stem length, was essentially prevented. Gibberellin was, therefore, ineffective in overcoming the salt‐induced suppression of growth. An increased rate of water use per unit leaf area was quite consistently observed with the gibberellin‐treated plants. This may be simply the result of the increased exposure to light and to air movement of leaves on an elongated stem.

Absorption and Translocation of 2,4-Dichlorophenoxyacetic Acid

1. The pronounced morphological response in plants to 2,4- dichlorophenoxyacetic acid is useful in studies of translocation. 2. The regulator passed upward but not downward through dead segments of stems. 3. Stomata did not appear to be important portals for entry of the compound into the leaves when it was used in aqueous sprays. Leaves of young soybeans absorbed maximum amounts of the growth regulator within 6 hours after application. 4. The movement of food materials was regulated by partial clipping of leaves, defoliation, and reduced light intensity. When the growth regulator was applied to aerial portions of plants, the substance readily moved downward whenever translocation of synthesized materials occurred. 5. More extensive growth inhibition of young red kidney bean plants at primary leaf stage resulted when the substance was added to the base of the blade than when added near the tip. When the compound was added to a primary leaf of a young bean plant more extensive growth inhibition resulted wh...