scholarly journals DROUGHT RESISTANCE OF Sorghum bicolor. 6. CHANGES IN ENDOGENOUS GROWTH REGULATORS OF PLANTS GROWN ACROSS AN IRRIGATION GRADIENT

1983 ◽  
Vol 63 (1) ◽  
pp. 147-155 ◽  
Author(s):  
T. KANNANGARA ◽  
R. C. DURLEY ◽  
G. M. SIMPSON ◽  
N. SEETHARAMA
Keyword(s):  
Abscisic Acid ◽  
Water Stress ◽  
Grain Yield ◽  
Leaf Area ◽  
Endogenous Growth ◽  
Plant Height ◽  
Growth Regulators ◽  
Leaf Temperature ◽  
Leaf Conductance ◽  
Phaseic Acid

A gradient of water stress was created among sorghum plants with a line-source sprinkler irrigation system. Changes in endogenous growth regulators, leaf water potential (ψw), solute potential (ψs), leaf conductance, leaf temperature, leaf senescence, leaf area and plant height were monitored. Abscisic acid (AbA) levels were increased and phaseic acid (PA) levels were reduced under stress. IAA levels could not be related to stress. Leaf ψw, leaf ψs and leaf conductance were reduced and leaf temperature was increased by water stress. Leaf area development was more sensitive to stress than stem elongation. Linear correlations between irrigation, AbA, leaf ψw, leaf ψs and plant height were high (r > 0.9). The correlation between AbA and grain yield (r = − 0.65) was similar to that between irrigation and grain yield (r = 0.68), but opposite in sign. Leaf AbA content measured during early growth could thus be used to predict grain yield under a given irrigation regime.Key words: Abscisic acid, phaseic acid, indole-3-acetic acid, water stress, grain yield, sorghum.

scholarly journals Combining Ability and Heterosis of Selected Grain and Forage Dual Purpose Sorghum Genotypes

2017 ◽  
Vol 9 (2) ◽  
pp. 122 ◽  
Author(s):  
Sally Chikuta ◽  
Thomas Odong ◽  
Fred Kabi ◽  
Patrick Rubaihayo
Keyword(s):  
Grain Yield ◽  
Leaf Area ◽  
Plant Height ◽  
Combining Ability ◽  
Gene Action ◽  
Small Scale ◽  
Dual Purpose ◽  
Forage Sorghum ◽  
Diallel Mating Design ◽  
Sorghum Genotypes

Sorghum is an important food and feed source in mixed crop-livestock production systems where its dual usage is a preferred option, especially among the resource poor small-scale farmers. Attempts to improve fodder quality traits in maize have been at the expense of grain traits and vice versa, but other studies demonstrated that it was possible to select for high stem biomass without compromising the improvement of grain yields in sorghum. As a follow up to this effort, this study was undertaken to estimate the combining ability of grain and forage sorghum genotypes and determine heterosis for several traits as a criteria for improving dual purpose sorghum cultivars. Four grain and four forage sorghum cultivars were crossed to generate 23 crosses following the half diallel mating design scheme at Makerere University Agricultural Research institute Kabanyolo (MUARIK) in 2013. The crosses were evaluated at three locations in Uganda during two rainy seasons of 2014. Data were taken and analysed on leaf area, leaf-stem ratio, plant height, seed weight, grain yield, and biomass. Results indicated that the gene action for the traits under observation was controlled by both additive and non additive genetic effects. Majority of the parental lines had significant GCA estimates for all traits except line 20 for grain yield, lines 22 and 34 for plant height, line 35 for leaf-stem ratio, and line 22 for days to flowering. Significant (P ≤ 0.05) SCA estimates were prominent in most of the individual parental combinations for all traits except leaf area and leaf-stem ratio indicating the role of dominance gene action. Bakers ratio and heritability coefficients were > 52% for biomass, flowering duration and plant height indicating that genetic gains can be achieved by conventional breeding for the three traits. Heterosis in grain yield and biomass over both the mid and better parents was shown by more than half of the crosses studied. This study suggested that both inter and intra allelic interactions were involved in the expression of the traits.

Effect of endophytic fungus Piriformospora indica on yield and some physiological traits of millet (Panicum miliaceum) under water stress

2018 ◽  
Vol 69 (6) ◽  
pp. 594 ◽  
Author(s):  
Goudarz Ahmadvand ◽  
Somayeh Hajinia
Keyword(s):  
Water Stress ◽  
Grain Yield ◽  
Leaf Area ◽  
Water Deficit ◽  
Flag Leaf ◽  
Piriformospora Indica ◽  
Physiological Traits ◽  
Water Deficit Stress ◽  
Panicum Miliaceum ◽  
Severe Water Stress

Piriformospora indica is one of the cultivable root-colonising endophytic fungi of the order Sebacinales, which efficiently promote plant growth, uptake of nutrients, and resistance to biotic and abiotic stresses. The aim of this study was to evaluate the effect of P. indica on millet (Panicum miliaceum L.) under water-stress conditions. Two field experiments were carried out in a factorial arrangement at Bu-Ali Sina University of Hamedan, Iran, during 2014 and 2015. The first factor was three levels of water-deficit stress, with irrigation after 60 mm (well-watered), 90 mm (mild stress) and 120 mm (severe stress) evaporation from pan class A. The second factor was two levels of fungus P. indica: inoculated and uninoculated. Results showed that water-deficit stress significantly decreased grain yield and yield components. Colonisation by P. indica significantly increased number of panicles per plant, number of grains per panicle and 1000-grain weight, regardless of water supply. Inoculation with P. indica increased grain yield by 11.4% (year 1) and 19.72% (year 2) in well-watered conditions and by 35.34% (year 1) and 32.59% (year 2) under drought stress, compared with uninoculated plants. Maximum flag-leaf area (21.71 cm2) was achieved with well-watered conditions. Severe water stress decreased flag-leaf area by 53.36%. Flag-leaf area was increased by 18.64% by fungus inoculation compared with the uninoculated control. Under drought conditions, inoculation with P. indica increased plant height by 27.07% and panicle length by 9.61%. Severe water stress caused a significant decrease in grain phosphorus concentration, by 42.42%, compared with the well-watered treatment. By contrast, grain nitrogen and protein contents were increased about 30.23% and 30.18%, respectively, with severe water stress. Inoculation with P. indica increased grain phosphorus by 24.22%, nitrogen by 7.47% and protein content by 7.54% compared with control. Water stress reduced leaf chlorophyll and carotenoid concentrations, whereas P. indica inoculation enhanced chlorophyll concentrations by 27.18% under severe water stress. The results indicated the positive effect of P. indica on yield and physiological traits of millet in both well-watered and water-stressed conditions.

scholarly journals DROUGHT RESISTANCE OF Sorghum bicolor. 5. GENOTYPIC DIFFERENCES IN THE CONCENTRATIONS OF FREE AND CONJUGATED ABSCISIC, PHASEIC AND INDOLE-3-ACETIC ACIDS IN LEAVES OF FIELD-GROWN DROUGHT-STRESSED PLANTS.

1983 ◽  
Vol 63 (1) ◽  
pp. 131-145 ◽  
Author(s):  
R. C. DURLEY ◽  
T. KANNANGARA ◽  
G. M. SIMPSON ◽  
N. SEETHARAMA
Keyword(s):  
Acetic Acid ◽  
Abscisic Acid ◽  
Grain Yield ◽  
Sorghum Bicolor ◽  
Drought Resistance ◽  
Genotypic Variation ◽  
Genotypic Differences ◽  
Phaseic Acid ◽  
Acid Yield ◽  
Indole 3 Acetic Acid

Concentrations of free and conjugated abscisic acid (AbA), phaseic acid (PA) and indole-3-acetic acid (IAA) were measured in leaves of sorghum (Sorghum bicolor (L.) Moench) genotypes grown in the field. Hormone levels were compared and related to grain yield stability under drought, expressed as the percentage reduction in grain yield (percent RGY) of drought-stressed compared to irrigated plants. Although hormone concentrations were similar in irrigated plants, there was considerable genotypic variation in drought-stressed plants. In a four genotype comparison during the panicle initiation stage, mean leaf AbA concentrations in drought-stressed plants were positively related to percent RGY. Furthermore, the slopes of regression lines of AbA on leaf water potential in stressed genotypes were also positively related to percent RGY. In contrast, PA and total AbA metabolite concentrations were negatively related to percent RGY, implying a higher efficiency of conversion of AbA to its metabolites in drought resistant than in drought-susceptible genotypes. There was genotypic variation in free and conjugated IAA concentration in leaves of stressed plants, but these concentrations were not directly related to percent RGY. Nevertheless, high levels of free and conjugated IAA were found at some periods in leaves of drought-susceptible genotypes. The positive relationship between free AbA concentration and percent RGY was confirmed in a nine genotype comparison. Mean leaf AbA concentrations during flowering and early grain filling in drought-stressed plants were found to be a significantly correlated (r = 0.86**) with percent RGY. It is concluded that it is possible to evaluate genotype drought resistance to a given stress treatment in sorghum by examination of AbA, PA and IAA concentations in leaves. The potential of the method as a tool for plant breeders is discussed.Key words: Sorghum bicolor, drought stress, abscisic acid, phaseic acid, indole-3-acetic acid, yield

scholarly journals Effects of plant growth regulators in heliconia ‘Red Opal’

2016 ◽  
Vol 22 (3) ◽  
pp. 301
Author(s):  
Ana Cecilia Ribeiro de Castro ◽  
Fernando José Hawerroth ◽  
Carlos Alberto Kenji Taniguchi ◽  
Tiago Freitas Silva ◽  
Nazaré Suziane Soares
Keyword(s):  
Leaf Area ◽  
Plant Height ◽  
Growth Regulators ◽  
Growth Regulator ◽  
Block Design ◽  
Dry Mass ◽  
Potted Plants ◽  
Randomized Block Design ◽  
Number Of Leaves ◽  
One Year

The objective of this study was to evaluate growth regulators with purpose of reducing the size of heliconia ‘Red Opal’ potted plants. The experiment was carried out in randomized block design with five treatments (trinexapac-ethyl and paclobutrazol at rates of 37.5 and 75.0 mg of active ingredient per pot and control without growth regulator) and five replicates. The treatments were applied 40 days after planting the rhizomes in pots filled with soil. Thirty and 150 days after the growth regulator application, plant height, number of leaves and shoots, petioles length and leaf area were evaluated. One year after planting the rhizomes in pots the number of inflorescence and leaves (leaves, sheathing leaf bases and inflorescences) and rhizomes (rhizomes and roots) dry mass were determined. Trinexapac-ethyl had no differences compared to the control in any of the variables evaluated. Paclobutrazol proved effective in reducing plant height, leaf area and petiole length and increase in number of leaves and shoots but the effect was temporary. Also, it did not affect the inflorescences production and leaves and rhizomes dry mass. Paclobutrazol is efficient to promote height reduction and to increase the number of shoots in heliconia ‘Red Opal’ potted plants without affect the inflorescence formation but its effects is temporary.

scholarly journals Effects of Pinching, Number of Cuttings per Pot, and Plant Growth Regulators on Height Control of Purple Firespike

2015 ◽  
Vol 25 (1) ◽  
pp. 71-75 ◽  
Author(s):  
Amir Rezazadeh ◽  
Richard L. Harkess
Keyword(s):  
Plant Growth ◽  
Leaf Area ◽  
Plant Height ◽  
Plant Growth Regulators ◽  
Growth Regulators ◽  
Stem Elongation ◽  
Dry Weight ◽  
Maximum Height ◽  
Height Control ◽  
Leaf Dry Weight

Purple firespike (Odontonema callistachyum), native to Central America, has potential for use as a new flowering potted plant. The effects of number of pinches (zero, one, or two) and number of cuttings (one, two, or three) per 6-inch pot were evaluated on the control of plant height. Plant height was suppressed as the pinch number increased. The greatest reduction was recorded with one cutting per pot and two pinches. The maximum number of branches per pot was recorded with two pinches and three cuttings per pot. In a second experiment, plant growth regulators (PGR) were also tested for efficacy of height control; 2 weeks after pinching, foliar sprays of paclobutrazol, flurprimidol, daminozide, chlormequat, and a tank-mix of daminozide + chlormequat or media drenches of paclobutrazol, uniconazole, or flurprimidol were applied. Plant height, leaf area, and leaf dry weight were recorded at 3, 6, and 9 weeks after PGR application. Maximum height control was obtained with uniconazole drench at 8 ppm, resulting in plants 22 cm tall, 61% shorter than the untreated control (56 cm); however, it resulted in severe leaf distortion. Plant height was 56% and 46% shorter than the control using drenches of paclobutrazol at 30 ppm and flurprimidol at 15 ppm, respectively. Daminozide spray at 2000 ppm and tank-mix of daminozide + chlormequat at 4500/1500 ppm suppressed stem elongation by 20.3% and 19%, respectively. Plants treated with paclobutrazol drench at 30 ppm reduced leaf area and leaf dry weight compared with other PGRs. Chlormequat spray at tested concentrations was ineffective for controlling firespike plant growth. The most attractive potted plants were produced using a drench application of paclobutrazol at 10 or 15 ppm.

scholarly journals Water Stress Limits Growth and Physiological Performance of Jatropha curcas L. Seedlings

2020 ◽  
pp. 47-53
Author(s):  
Bassirou Sine ◽  
Bassiaka Ouattara ◽  
Diariétou Sambakhé ◽  
Alassane Waly Ngom ◽  
Aïda Ndiaye
Keyword(s):  
Water Stress ◽  
Stomatal Conductance ◽  
Plant Height ◽  
Jatropha Curcas ◽  
Climatic Conditions ◽  
Leaf Temperature ◽  
Arid Zones ◽  
Jatropha Curcas L ◽  
Collar Diameter ◽  
Semi Arid

Jatropha (Jatropha curcas L.) is a potential biodiesel plant that gained much attention in non-oil production countries. We investigated the ability of the species to cope with water deficit occurring in semi-arid zones like Senegal climatic conditions. The layout of the experiment was a randomized complete blocks design with two factors (level and frequency of irrigation) and 6 repetitions. The trial was conducted from December 2012 to June 2013 in CERAAS/ISRA at Thiès, Senegal. Potted Jatropha seedlings were exposed, after three months under similar well-watered conditions, to three water regimes (100%, 50% and 25% of field capacity, respectively C100, C50 and C25) and two frequency of watering once and twice watering a week(F1 and F2, respectively). The different treatments didn’t affect significantly collar diameter and plant height during the time of the experimentation. Nevertheless, the trend line is up for collar diameter and plant height in well-watered plants. For the same frequency of irrigation, biomass accumulated was high in C100. No difference was found between plants biomass in C25-F1 and C25-F2. For physiological parameters, there are no differences between the treatments at the onset of stress. However, after 2 weeks of stress, photosynthesis, stomatal conductance and transpiration were affected permanently in treatments C100-F1, C50-F1 and C25-F1 and their values never reached those of plants of C100-F2, 50-F2 and C25-F2. The opposite was noted for leaf temperature. For the same frequency of irrigation, photosynthesis, stomatal conductance and transpiration were higher in C100 and the opposite occurred for the leaf temperature. These results demonstrate that growth and productivity of Jatropha are significantly affected by water stress conditions. Its need to be watered regularly to maintain physiological functions and biomass production definitely highlights that its growth in semi-arid zones is economically unlikely.

scholarly journals Effect of Spacing and Nitrogen Level on Growth and Yield of Maize (Zea mays L.) in Mid hill of Nepal

2020 ◽  
Vol 3 (2) ◽  
pp. 50-55
Author(s):  
Ramhari Gaire ◽  
Chudamani Pant ◽  
Nischal Sapkota ◽  
Rajan Dhamaniya ◽  
Tej Narayan Bhusal
Keyword(s):  
Grain Yield ◽  
Leaf Area Index ◽  
Leaf Area ◽  
Plant Height ◽  
Block Design ◽  
Organic Matter Content ◽  
Growth And Yield ◽  
Nitrogen Level ◽  
Area Index ◽  
Close Spacing

AbstractA field experiment was carried out to study the effect of spacing and nitrogen level on growth and yield of maize in Parbat from February to July, 2019. The experiment was laid out in two Factorial Randomized complete Block Design (RCBD) comprising of spacing: 60×15 cm and 60×25 cm and nitrogen: 30, 60, 90 and 120 kg/ha level as treatment with three replications. “Arun-2” variety of maize was planted on clay loam and acidic soil (pH 5.3) having medium in total nitrogen (0.15%), medium in soil available phosphorus (48.1 kg/ha), medium in soil available potassium (218.8 kg/ha) and medium in organic matter content (2.92%). Result shows that yield was significantly increased with increment in N-level up to 90 kg N/ha. The grain yield (5.18 mt/ha) was significantly higher at 90 kg N/ha than at 30 and 60 kg N/ha but at par with 120 kg N/ha. Significant effect on grain yield due to spacing was observed. The grain yield (4.11 mt/ha) obtained at spacing 60×15 cm. Moreover, the highest grain yield showed that highest grain yield (4.33 mt/ha) was obtained under 90 kg N/ha plus 60×15 cm spacing. The result revealed that different spacing and nitrogen level significantly affect the plant height and leaf area index. The plant height and leaf area index were significantly high at close spacing (60×15 cm) and at 120 kg N/ha. Likewise, yield attributing characteristics like cob length, cob diameter, number of kernel/rows, number of kernel row, thousand gran weight were the highest at 90 kg/ha but as par with 120 kg/ha at close spacing (60×15 cm). This study suggested that maize production can be maximized by cultivating “Arun-2” maize fertilizing with 90 kg N/ha and maintaining 60×15 cm spacing.

scholarly journals Reguladores de crescimento na redução do porte da orquídea Estrela-de-Fogo para comercialização em vaso

2016 ◽  
Vol 22 (1) ◽  
pp. 114
Author(s):  
Patricia Reiners Carvalho ◽  
Ricardo Tadeu Faria ◽  
Christina Da Silva Wanderley ◽  
Nelson Barbosa Machado Neto ◽  
Oscar De Andrade Junior
Keyword(s):  
Regression Analysis ◽  
Leaf Area ◽  
Plant Height ◽  
Analysis Of Variance ◽  
Growth Regulators ◽  
Adventitious Roots ◽  
Average Height ◽  
Terrestrial Orchid ◽  
Flowering Stem ◽  
Aesthetic Characteristics

Fire-of-star (Epidendrum radicans Pav. ex Lindl.) is a terrestrial orchid, native to Brazil, tussocks with leafy stems, always with many adventitious roots, releasing its long inflorescence with about 1.0 m from the apex of the stem, showing great potential in floriculture, but long flowering stem complicates their marketing vase. The objective of this study was to evaluate the effect of paclobutrazol (PBZ) and mepiquat chloride (CLM) the reduction of the size of the orchid E. radicans. Plants with an average height of 15 cm were cultivated in a greenhouse with 50% shading. The growth regulators used were PBZ at doses of 0; 5; 10; 15 and 20 mg L-1, and the CLM at doses of 0; 1; 2; 3; 4 and 5 mg L-1. The frequency of application was fortnightly, totaling ten applications. The experiment was installed on a randomized complete blocks, one block to the PBZ with 5 treatments and 10 replications and another block to the CLM, with 6 treatments and 10 replications. Data were submitted to analysis of variance at 5% probability and significance when seen performed regression analysis. The variables evaluated were number shoots, plant height (cm), number of flower stems and leaf area. The results indicated that E. radicans treated with 5 mg L-1 PBZ were 50% lower in height than the control plants. When CLM treated with a dose of 1 mg L-1 plants were 25% lower in height than the control plants, maintaining its aesthetic characteristics suitable for marketing in vases. Growth regulators in the applied doses did not affect the number of shoots and flower stems. PBZ treated plants had 50% of their leaf area compared to control while those treated with CLM doses remained with the same average leaf area of control.

scholarly journals GENETIC ANALYSIS AND SELECTION CRITERIA IN ADVANCED BREEDING LINES OF DEEP WATER RICE

2007 ◽  
Vol 20 (1) ◽  
pp. 39-45
Author(s):  
Khaleda Akter ◽  
S. H. Habib ◽  
M. K. Bashar ◽  
A. M. Nurunnabi
Keyword(s):  
Grain Yield ◽  
Leaf Area ◽  
Plant Height ◽  
Deep Water ◽  
Indirect Effect ◽  
Harvest Index ◽  
Flag Leaf ◽  
Path Coefficient ◽  
Panicle Length ◽  
Breeding Lines

Thirty advanced breeding lines of deep-water rice were evaluated during T. Aman season (rainfed ecosystem) with a view to finding out variability and genetic association for grain yield and its component characters. All the tested characters showed significant variation. The highest genetic variability was obtained in filled grains/panicle followed by plant height. Panicles/plant, filled grains/panicle and grain yield had high genetic coefficient of variation and heritability in broad sense coupled with high genetic advance in percentage of mean. Panicle length, panicles/plant, plant height, filled grains/panicle and harvest index showed significant positive association with grain yield. Path coefficient analysis also revealed maximum positive and direct contribution of filled grain to grain yield followed by panicles/plant, 1000-grain weight and flag leaf area. Moreover, plant height had the highest indirect effect on grain yield through filled grains/panicle. Flag leaf area, harvest index and panicle length also had higher positive indirect effect on grain yield through filled grains/panicle.DOI: http://dx.doi.org/10.3329/bjpbg.v20i1.17024

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