Gibberellic acid-sensitive dwarfing genes reduce plant height to increase kernel number and grain yield of wheat

2000 ◽  
Vol 51 (2) ◽  
pp. 235 ◽  
Author(s):  
G. J. Rebetzke ◽  
R. A. Richards
Keyword(s):  
Gibberellic Acid ◽  
Grain Yield ◽  
Plant Height ◽  
Harvest Index ◽  
Genotypic Variation ◽  
Genotypic Differences ◽  
Dwarfing Genes ◽  
Kernel Number ◽  
Coleoptile Length ◽  
Reduced Height

The Norin-10 dwarfing genes, Rht-B1b (Rht1) and Rht-D1b (Rht2), have been used to reduce plant height and increase grain yield in wheat breeding programs worldwide. Other dwarfing genes are available to reduce plant height of wheat but little is known of their effects on grain yield. A set of random, F5-derived wheat lines containing either minor genes for reduced plant height, or major gibberellic acid (GA) sensitive Rht8 and Rht9 dwarfing genes, were obtained from 3 different populations. Environment mean yields ranged from 2.5 to 4.6 t/ha. Genotypic variation was large and significant (P < 0.05) for plant height, grain yield and its components, and kernel number and size. Approximately 30% of lines were as short as variety Hartog, while kernel number per m2, harvest index, and grain yield of the shortest GA-sensitive lines were not significantly different (P < 0.05) from the commercial semidwarf checks Janz or Hartog. Furthermore, genotypic differences in plant height were genetically correlated (rg) with variation in kernel number (rg = −0.76*), harvest index (−0.71*), and grain yield (−0.62*). These correlated effects were confirmed with retrospective selection for height and were consistent with reported height effects of Rht-B1b and Rht-D1b dwarfing genes on kernel number and harvest index in wheat. Plant height differences among GA-sensitive lines were independent of variation in seedling characteristics (r2 = 0.01–0.02 n.s.), while a number of reduced-height lines produced 50% longer coleoptiles and greater seedling biomass than Janz. These studies demonstrate a correlation between the shorter height of GA-sensitive dwarfing genes and increased grain yield, and suggest their potential for improving wheat establishment through greater coleoptile length and early vigour.

scholarly journals STUDIES ON INCREASED PLANT POPULATION OF DIFFERENT VARIETIES OF MAIZE (Zea mays L) IN YOLA AND MUBI, ADAMAWA STATE, NIGERIA

2019 ◽  
Vol 7 (4) ◽  
pp. 14-36
Author(s):  
Mamudu Njodi ◽  
Mohammed D. Toungos ◽  
Mu’azu Babayola ◽  
Hassan Kashim
Keyword(s):  
Grain Yield ◽  
Plant Height ◽  
Harvest Index ◽  
Yield Component ◽  
Plant Population ◽  
Cropping Season ◽  
Maize Varieties ◽  
Significant Difference ◽  
Main Plot ◽  
Number Of Leaves

Field experiment were conducted at Yola and Mubi locations to study the effects of increased plant population of five (5) varieties of maize Viz:  SAMMAZ 11, SAMMAZ  14, SAMMAZ 15, SAMMAZ 16, and SAMMAZ 17 on yield and yield component during the 2011 cropping season. The experimental design was a split plot design with maize varieties as the main plot treatments, while plant population, (53,333, 63,333, 80,000 and 106,666) as the sub-plot treatments. The treatment were replicated three (3) times. Characters measured included plant height, number of leaves per plant, number of days to 50% tasseling, number of day to 50 % silking, days to 95% maturity, number of ear per plant, stem diameter, length of ear, diameter of ear, number of grains per ear, 100 grain weight, number of grains per ear. Yield per plot and total grain yield per hectare. The result of the experiments showed that there was significant difference due to varietal effect in plant height at 3 WAS in Yola and at 7 WAS and 9 WAS in Mubi. Variety also affects days to 50% tasseling, days to 50% silking and days to 95% maturity at both locations. Variety also affects ear length at both locations. Interaction of variety and population affected harvest index in Mubi. Population significantly affected yield per plant, yield per plot, total grain yield per hectare in both locations. Combined analysis result showed highly significant effect due to location on plant height at 3 and 5 WAS and also due to variety. Location also affected number of leaves per plant significantly at 3WAS and highly significantly at 5, 7, 9 and 11 WAS. Varieties affected number of leaves per plant at 5 and 9 WAS and was highly significant at 11 WAS.  Location and varieties affected days to 50% tasseling, days to 50 % silking and days to 95% maturity, while population only affected days to 50% silking. Diameter of ear and harvest index was highly significant by location and on number of grains per row. Varieties also showed significant differences in length of ear. Location affected straw weight per plant, while varieties affected yield per plant and yield per plot, weight of 100 grain yield and total grain yield per hectare was also highly significantly affected. Population affected yield per plant, especially the ones in Yola. Straw weight, total grain yield and weight of 100 grain were significantly affected. SAMMAZ 15 which gave a plant population of 106,666 ha-1 is recommended at both locations.

Heterosis, overdominance for grain yield, and alpha-amylase activity in F1 hybrids between near-isogenic Rht dwarf and tall wheats

1997 ◽  
Vol 129 (4) ◽  
pp. 371-378 ◽  
Author(s):  
J. E. FLINTHAM ◽  
W. J. ANGUS ◽  
M. D. GALE
Keyword(s):  
Grain Yield ◽  
Amylase Activity ◽  
Single Gene ◽  
Preharvest Sprouting ◽  
Alpha Amylase ◽  
F1 Hybrids ◽  
Dwarfing Genes ◽  
Heterozygous Condition ◽  
Reduced Height ◽  
Continuous Range

The Rht-B1b, Rht-D1b and Rht-B1c alleles for reduced height in wheat (the Norin 10 and Tom Thumb dwarfing genes previously known as Rht1, Rht2 and Rht3) were exploited in combinations to generate a near-continuous range of plant heights, from 53 cm to 123 cm, amongst near-isogenic homozygotes and F1 hybrids. Pleiotropic yield effects of Rht genes were measured in both homozygous (intravarietal) and heterozygous (intervarietal) genetic backgrounds. Heterosis due to overdominance of Rht genes was detected among intravarietal hybrids. The effects of heterozygosity at other genetic loci (mean dominance) were determined, independently of Rht effects, from comparisons between intravarietal and intervarietal F1 hybrids.Genotypes of intermediate plant heights gave maximum yields, in agreement with other trials of the homozygous lines, so that heterosis (hybrid exceeding best parent) for Rht yield effects was observed in crosses between tall and dwarf isogenic pairs. This heterosis combined additively with increased mean weight per grain in intervarietal crosses, generating the highest overall grain yields in hybrids with semi-dwarf stature in heterozygous genetic backgrounds. The Rht-B1c allele showed single-gene overdominance for grain yield, also the production of alpha-amylase in ripening grains of Maris Huntsman was effectively inhibited in the Rht-B1a/c intravarietal hybrid. The Rht-B1c allele thus offers advantages for both grain yield and grain quality in the heterozygous condition and should be considered as an alternative to the conventional semi-dwarfing genes Rht-B1b and Rht-D1b for F1 varieties in environments conductive to preharvest sprouting.

scholarly journals Evaluation of Performances of Cowpea (Vigna ungiculata) Genotypes in Agronomy Farm of Lamjung Campus

2017 ◽  
Vol 5 (3) ◽  
pp. 382-385
Author(s):  
Chandan Bhattarai ◽  
Dinesh Marasini ◽  
Prabin Dawadi ◽  
Sadkishya Aryal
Keyword(s):  
Data Collection ◽  
Grain Yield ◽  
Plant Height ◽  
Seed Production ◽  
Seed Weight ◽  
Harvest Index ◽  
Yield Parameters ◽  
Cowpea Varieties ◽  
Pod Length ◽  
The Given

Seed to seed production experiments for cowpea (Vigna ungiculata) was conducted at Agronomy farm at IAAS Lamjung, and to compare production potentialities of given cowpea genotypes under the given sets of conditions. The treatment consists of two cowpea varieties viz. Prakash (Standard Check) and Malepatan (Local check) and four genotypes; IT 99K-573-2-1, IT 86F-2062-5, IT 93K-452-1, IT 98K-205-8. The experiment was conducted on RCBD design. .All other activities were carried out according to prepared working calendar almost from August 2016 to December 2016.  Data collection were done for pre-determined growth and other yield parameters and was analyzed using MSTAT. Major parameters were Grain yield, Seeds/plant, Pods/plant, plant height, pod length, harvest index and test weight. Result shows maximum grain yield and harvest index was found for Prakash (Standard Check).Plant height and Pods /Plant was found highest for IT 99K-573-2-1. Similarly highest seed weight was found for Prakash (Standard Check) and Seeds/Plant and Pod length was maximum for IT 86F-2062-5.Int. J. Appl. Sci. Biotechnol. Vol 5(3): 382-385

scholarly journals Effect of different tillage practices and nitrogen level on wheat production under inner terai of Nepal

2020 ◽  
Vol 3 (1) ◽  
pp. 233-239 ◽  
Author(s):  
Sampurna Bartaula ◽  
Urbasi Panthi ◽  
Anil Adhikari ◽  
Mohan Mahato ◽  
Darbin Joshi ◽  
...  
Keyword(s):  
Grain Yield ◽  
Plant Height ◽  
Harvest Index ◽  
Nitrogen Level ◽  
Zero Tillage ◽  
Significant Relation ◽  
Tillage Practice ◽  
Tillage Practices ◽  
N Level ◽  
Biological Yield

A field experiment was conducted to evaluate the plant height, yield and yield attributes of wheat under different tillage practices and nitrogen level at Dang, Nepal during winter season 2018-19. The experiment was laid out in split plot design with two tillage practices viz. zero tillage and conventional tillage as main plot factor and four level of N viz. 50 kg ha-1, 75 kg ha-1, 100 kg ha-1and 125 kg ha-1 as sub plot factor and each replicated thrice.  The result revealed that there is no significant relation between tillage practice and plant height of wheat while N level significantly affect the plant height. 125 kg N ha-1 recorded the highest plant height (110.7 cm). Zero tillage recorded the highest effective tiller m-2 (254) and grain yield (3.3 t ha-1) whereas spike length, grain spike-1, biological yield and harvest index were not significant with tillage practices. Regarding the N level, 125 kg N ha-1 recorded the highest effective spike m-2 (279), spike length (10.6 cm), grain spike-1 (48), thousand grain weight (46.3 g), grain yield (3.6 t ha-1) and biological yield (9.4 t ha-1). 50 kg N ha-1 recorded the highest harvest index (42.9%). The interaction between the tillage practice and nitrogen level showed the significant effect on grain yield and harvest index where as other parameters showed non-significant relation. The zero tillage with 125 kg N ha-1 recorded the highest grain yield (3.9 t ha-1).

scholarly journals Effect of level of irrigation and nitrogen rate on yield performance of late sown wheat

2018 ◽  
Vol 29 (3) ◽  
pp. 213-220
Author(s):  
S Kazi ◽  
SU Bhuiya ◽  
AK Hasan ◽  
RR Rajib ◽  
ABMR Rahman ◽  
...  
Keyword(s):  
Grain Yield ◽  
Plant Height ◽  
Harvest Index ◽  
Grain Weight ◽  
Spike Length ◽  
High Dose ◽  
Nitrogen Rate ◽  
Irrigation Level ◽  
1000 Grain Weight ◽  
Late Sowing

The experiment was at the Agronomy Field Laboratory, Bangladesh Agricultural University, Mymensingh–2202 during late Rabi season (December-March) of 2015. It was two factorial experiment (1) irrigation level and (2) nitrogen rate. Irrigation significantly influenced on yield and yield contributing characters except harvest index. The highest plant height (79.69cm), maximum number of total tillers plant-1 (4.725), number of grains spike-1 (40.61), spike length (11.80cm), 1000 grain weight (28.67g), grain yield (3.227 t ha-1), harvest index (41.26%) were obtained by mulching treatment. Nitrogen rate significantly influenced the yield and yield contributing characters. The highest plant height (80.37cm), maximum number of total tillers plant-1 (5.124), number of grains spike-1 (40.85), spike length (10.37cm), 1000 grain weight (31.86g), grain yield (3.792 t ha-1), harvest index (41.69%) were obtained by the application of 180 kg N ha-1. The combined effect of Irrigation and nitrogen significantly interacted on yield and yield contributing characters. The highest plant height (83.44cm), number of total tillers plant-1 (5.66), number of grains spike-1 (41.60), 1000 grain weight (36.66g), grain yield (4.32 t ha-1) and harvest index (47.36%) were obtained by application of 180 kg N ha-1 with mulching. The present study revealed that high dose of nitrogen 180 kg ha-1 and mulching practice can compensate low production of wheat even at late sowing. Progressive Agriculture 29 (3): 213-220, 2018

scholarly journals Evidence for genotypic differences among elite lines of common bean in the ability to remobilize photosynthate to increase yield under drought

2016 ◽  
Vol 155 (6) ◽  
pp. 857-875 ◽  
Author(s):  
I. M. RAO ◽  
S. E. BEEBE ◽  
J. POLANIA ◽  
M. GRAJALES ◽  
C. CAJIAO ◽  
...  
Keyword(s):  
Drought Stress ◽  
Grain Yield ◽  
Common Bean ◽  
Harvest Index ◽  
Genotypic Differences ◽  
Area Index ◽  
Wild Bean ◽  
Terminal Drought ◽  
Terminal Drought Stress ◽  
Pod Harvest Index

SUMMARYCommon bean (Phaseolus vulgaris L.) is the most important food legume for human consumption. Drought stress is the major abiotic stress limitation of bean yields in smallholder farming systems worldwide. The current work aimed to determine the role of enhanced photosynthate mobilization to improve adaptation to intermittent and terminal drought stress and to identify a few key adaptive traits that can be used for developing drought-resistant genotypes. Field studies were conducted over three seasons at Centro Internacional de Agricultura Tropical, Palmira, Colombia to determine genotypic differences in adaptation to intermittent (two seasons) and terminal (one season) drought stress compared with irrigated conditions. A set of 36 genotypes, including 33 common bean, two wild bean and one cowpea were evaluated using a 6 × 6 lattice design under irrigated and rainfed field conditions. Three common bean elite lines (NCB 226, SEN 56, SER 125) were identified with superior levels of adaptation to both intermittent and terminal drought stress conditions. The greater performance of these lines under drought stress was associated with their ability to remobilize photosynthate to increase grain yield based on higher values of harvest index, pod harvest index, leaf area index and canopy biomass. Two wild bean germplasm accessions (G 19902, G 24390) showed very poor adaptation to both types of drought stress. One small-seeded black line (NCB 226) was superior in combining greater values of canopy biomass with greater ability to mobilize photosynthates to grain under both types of drought stress. Two small-seeded red lines (SER 78, SER 125) seem to combine the desirable traits of enhanced mobilization of photosynthates to seed with effective use of water through canopy cooling under terminal drought stress. Pod harvest index showed significant positive association with grain yield under both types of drought stress and this trait can be used by breeders as an additional selection method to grain yield in evaluation of breeding populations for both types of drought stress.

scholarly journals Response of transplanted aman rice varieties to split application of potassium

2018 ◽  
Vol 5 (3) ◽  
pp. 313-320
Author(s):  
Israt Jahan ◽  
Sarder Md Altaf Hossain ◽  
Md Anwarul Islam ◽  
Joynulalam Talukder
Keyword(s):  
Grain Yield ◽  
Plant Height ◽  
Harvest Index ◽  
Experimental Plot ◽  
Split Application ◽  
Rice Varieties ◽  
Straw Yield ◽  
Plot Size ◽  
Biological Yield ◽  
Equal Split

The research was conducted at the Agronomy Field Laboratory, Bangladesh Agricultural University, Mymensingh, to investigate the effect of time of split application of potassium on the yield of three transplanted (T) aman rice varieties. Rice varieties were BRRI dhan39, BRRI dhan40 and BRRI dhan41. Potassium was applied at the rate of 80 kg K ha-1. Experimental plot size was 5m2 (2.5m ×2.0m). Four split application of potassium [K1= Control (No K application), K2= 40 g K plot-1 at 15 DAT (days after transplanting), K3= 20 g K plot-1 at15 DAT+20 g K plot-1 at 30DAT, K4= 10 g K plot-1 at 15 DAT+ 10 g K plot-1 at 25DAT+ 10 g K plot-1 at 30 DAT+ 10 g K plot-1 at 45 DAT] were considered as treatments. From the experiment it was found that split application of potassium had no significant effect on plant height, length of panicle, thousand grains weight. It was evident that two splits application of potassium i.e., 20 g K plot-1 at 15 DAT+20 g K plot-1 at 30 DAT with BRRI dhan41 gave maximum no. of tiller hill-1, effective tiller hill-1, grains panicle-1, grain yield and straw yield, biological yield and harvest index. But varieties differed among themselves in terms of yield contributing characters and yield, and BRRI dhan41 performed the best. Therefore, based on the findings of the present study, it may be concluded that for obtaining higher yield BRRI dhan 41 can be grown following application of potassium at the rate of 80 kg ha-1 in two equal split at 15 and 30 days after transplanting Res. Agric., Livest. Fish.5(3): 313-320, December 2018

CONTRIBUTION OF GROWTH RATE AND HARVEST INDEX TO GRAIN YIELD IN F9-DERIVED LINES OF OATS (AVENA SATIVA L.)

1980 ◽  
Vol 60 (2) ◽  
pp. 379-384 ◽  
Author(s):  
K. TAKEDA ◽  
K. J. FREY ◽  
T. B. BAILEY
Keyword(s):  
Growth Rate ◽  
Grain Yield ◽  
Plant Height ◽  
Avena Sativa ◽  
Harvest Index ◽  
Heading Date ◽  
Genotypic Correlations ◽  
Day Plot

The contributions of growth rate (GR) and harvest index (HI) to grain yield (GYD) were studied using 1200 F9-derived lines of oats tested for 2 yr. Heritability ranged from 20 to 40% for GYD, GR, and HI. Genotypic correlations of GYD with GR were ca. 0.7 and with HI ca. 0.3. More than 95% of GYD variation was due to GR and HI. An increase of 0.1 g/day/plot GR would result in a 14% increase in GYD, and a 5% increase of HI would cause an 18–19% increase in GYD. GR was positively correlated with heading date and plant height, and negatively with HI.

Variation in south Asian wheat germplasm for seedling drought tolerance traits

2009 ◽  
Vol 7 (1) ◽  
pp. 88-93 ◽  
Author(s):  
Umesh R. Rosyara ◽  
Amrit A. Ghimire ◽  
Sushil Subedi ◽  
Ram C. Sharma
Keyword(s):  
Grain Yield ◽  
Field Experiments ◽  
Wheat Breeding ◽  
Dwarfing Genes ◽  
Seedling Vigour ◽  
Coleoptile Length ◽  
Wide Range ◽  
Dry Conditions ◽  
Breeding Programmes ◽  
Positive Correlations

Higher seedling vigour and greater coleoptile length are important for early establishment of wheat crops and subsequently higher grain yield in many dry environments. Seedling vigour includes those seed properties that determine the potential for rapid, uniform emergence and development of normal seedlings under a wide range of field conditions. Genotypes with the widely used gibberellic acid (GA)-insensitive dwarfing genes Rht-B1b and Rht-D1b have good partitioning and grain yield under optimal conditions, but may perform poorly under stressed conditions due to poor crop establishment. Breeding programmes are in search of GA-sensitive dwarfing genes that do not affect seedling vigour under dry conditions. This study evaluated 40 genotypes currently used in wheat breeding programmes of south Asia for seedling vigour-related traits in greenhouse and field experiments during 2006–2007 at IAAS, Rampur, Nepal. Wide variation in coleoptile length, seedling vigour, as well as sensitivity to GA was observed. Among the genotypes studied, there were positive correlations among coleoptile length, leaf width and plant height. Genotypes, SW89-5193, SW89-5422/NL251 and SW89-5422, were found to have longer coleoptile, higher seedling vigour and response to GA application. This shows a promise for their further applications in the breeding programmes.

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

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