Genetic effects of yield and root parameters in rice (Oryza sativa L.) at reproductive stage drought stress as apportioned by generation mean analysis

Author(s):  
P Yogameenakshi ◽  
P Vivekanandan ◽  
N Nadarajan

The nature of gene action governing important quantitative traits viz.yield and drought tolerance in rice were studied through six parameter model of generation means analysis using six generations (viz., P1, P2, F1, F2, BC1 and BC2) of five crosses by imposing drought stress at reproductive stage. Additive gene action was noticed for the traits like days to flowering, panicle length, 100 grain weight and root thickness in majority of the crosses while the yield characters like productive tillers / plant, filled grains / panicle, harvest index and grain yield / plant and the drought tolerant characters like spikelet fertility, root length and root / shoot ratio were governed by dominance gene action. Both additive and dominance effects were found in panicle length in the cross Kallurundaikar / Moroberekan; spikelet fertility, dry root weight, root/shoot ratio and grain yield / plant in the cross Norungan / Moroberekan and 100 grain weight and root thickness in the cross PMK 2 / Moroberekan. Interaction effects mainly of additive x additive was noticed in panicle length, filled grains /panicle, dry root weight and root/shoot ratio in most of the crosses while dominance x dominance gene action was predominant in 100 grain weight and both additive x dominance and dominance x dominance in days to flowering and plant height.

2016 ◽  
Vol 8 (2) ◽  
pp. 674-682
Author(s):  
V. Karpagam ◽  
S. Jebaraj ◽  
S. Rajeswari

Rice is the most important staple food for more than half of the world’s population and also for most of the countries. A Line x Tester analysis was undertaken to study the nature of gene action for yield and drought tolerant traits. The ratio of SCA and GCA was less than unity for all the characters which revealed that the preponderance of non- additive gene action governing the traits concerned. The lines viz., ADT 43, ADT (R) 49, CO (R) 50 and the testers viz., PMK (R) 3, Chandikar and Anna (R) 4 were adjudged as the best general combiners for drought tolerant traits. The cross combinations viz., ADT 39 x Vellaichitraikar had exhibited significant values for dry root weight (9.66), root/shoot ratio (0.31), root length (3.82), number of roots per plant (37.08), root thickness (0.11), root volume (4.27) and root length density (0.03) ADT (R) 49 x Chandikar for 70 percent relative water content (8.85), dry root weight (18.03), dry shoot weight (40.55), root length (3.10), number of roots per plant (140.16) root thickness (0.38) and root volume (23.14) were found to be specific combiners for most of the drought tolerant traits. The cross combinations, viz., ADT 43 x Anna (R) 4, ADT (R) 49 x Chandikar and ADT 43 x PMK (R) 3 had highly significant standard heterosis. Breeding for drought tolerance in rice would be of immense value to the farmers economic health, family well-being and harmony in the society.


2020 ◽  
Vol 7 (2) ◽  
pp. 51-61
Author(s):  
Manoj Kandel ◽  
Suk Gurung ◽  
Narayan Dhami ◽  
Jiban Shrestha

Analysis of genetic diversity and variability is an initial step for crop development in a plant breeding program. Thirty foxtail millet genotypes were evaluated for their ten agro-morphological traits viz. grain yield, days to heading, days to maturity, plant height, leaf length, leaf width, number of nodes per tiller, panicle length, thousand-grain weight, and leaf blast during April to August season of 2018 at Kabre, Dolakha, Nepal. Clustering was done based on variability observed among the genotypes for all the ten traits by the average linkage method. The genotypes were grouped into six clusters. The shortest inter cluster distance between Cluster I and Cluster II was 17.63 and the longest was between Cluster IV and Cluster VI with 47.55. Cluster I had the maximum leaf blast score with the minimum leaf length. The Cluster II had the maximum grain yield and days to 50% heading and the number of nodes per tiller. The Cluster III was characterized by the maximum leaf length and leaf blast value. The genotypes grouped into the Cluster IV were characterized by the lowest value of days to 50% heading and 80% days to maturity and those of Cluster V had the maximum thousand-grain weight. The genotypes categorized into Cluster VI had the maximum plant height, leaf length, and panicle length. Cluster II and Cluster V were good because of their agro-morphological traits. The presence of a high level of diversity among the genotypes indicated their suitability for selection in crop breeding programs. Correlation analysis of genotypes having the maximum panicle length leaf area and higher plant height and shorter maturity period are pre-requisite for improvement in grain yield.


2021 ◽  
Vol 22 (2) ◽  
pp. 92
Author(s):  
Sashi Lamichhane ◽  
Nav Raj Adhikari ◽  
Bishwas K.C. ◽  
Sapana Thapa

<p>Rice is an essential staple food in Nepal but researches and varietal improvement programs are rarely carried out due to inadequate variability study. The field study was carried to diagnose the influence of genetic and environmental factors on yield traits to aid future rice breeding programs. Twelve genotypes were arranged in randomized complete block design with three replications from July to November 2019 at the research field of the Institute of Agriculture and Animal Science, Tribhuvan University, in the hilly area of Nepal. Analysis of variance showed significant difference for days to 50% booting, days to 50% flowering, plant height, panicle length, flag leaf area, filled grains per panicle, unfilled grains per panicle, fertility percentage, effective tillers m<sup>-2</sup>, straw yield, grain yield, 1000-grain weight, and harvesting index indicating the presence of variation in genotypes. LPN BR-1615 was the most promising genotype in grain yield. The values of Phenotypic Coefficient of Variation (PCV) were higher than Genotypic Coefficient of Variation (GCV) for each trait and low difference between them was found for days to 50% booting, days to 50% flowering, plant height, panicle length, grain yield, thousand-grain weight, fertility percentage, and harvesting index. Plant height, effective tillers m<sup>-2</sup>, and grain yield showed high heritability (i.e. 93.2%, 60.5% and 92.6%, respectively) and higher genetic advance as percentage of mean (i.e. 46.5, 34.6 and 50.1, respectively) . Thus, the experiment revealed that selections favoring plant height, effective tillers m<sup>-2</sup>, and grain yield would help in effective breeding programs of rice in future.</p>


2002 ◽  
Vol 20 (2) ◽  
pp. 127-132
Author(s):  
Edward F. Gilman ◽  
Ann Stodola ◽  
Michael D. Marshall

Abstract Cutting propagated Quercus virginiana ‘QVTIA’ Highrise™ PP #11219 and seedling live oak required the same amount of time to prune to a dominant leader in the nursery. Highrise™ live oaks were more uniform in caliper, height and root ball characteristics than the seedling crop. Finished seedling trees had larger caliper than cutting propagated Highrise™ but height was similar. Root pruning horizontal roots alone or in combination with placing root pruning fabric under the liner at planting reduced dry weight of roots in the root ball by reducing large-diameter root weight and increasing small-diameter root weight. Trees produced by both methods of root pruning survived the digging process better than non root-pruned trees in the summer digging season. Seedlings had more root weight in the root ball and a higher root: shoot ratio than Highrise™ live oak. But Highrise™ had a 45% greater small diameter root: shoot ratio than seedling live oak, and more Highrise™ survived the digging process than seedlings. Highrise™ may not need root pruning during production if dug in the dormant season.


2015 ◽  
Vol 2 (2) ◽  
pp. 261-269
Author(s):  
Shompa Rani Debnath ◽  
Md Sultan Uddin Bhuiya ◽  
M Rafiqul Islam ◽  
Md Mahboob Karim ◽  
ABM Shafiul Alam

The experiment was conducted at the Agronomy Field Laboratory, Bangladesh Agricultural University, Mymensingh during July to December 2013 in the aman season to investigate the effect of age of seedling and nitrogen rates in the nursery bed on growth, yield and yield components of BRRI dhan52. The experiment comprised of three ages of seedlings viz., 30, 35 and 40 day old and four nitrogen rate N1-N@50 kg ha-1, N2-N@75 kg ha-1, N3-N@100 kg ha-1, N4-N@125 kg ha-1. The experiment was laid out in a split plot design with three replications. Age of seedling showed significant differences for shoot weight, survivor, no. grains panicle-1, panicle length, grain yield and straw yield. The highest root weight (0.072 gm-2), plant height (108 cm), total tillers hill-1 (8.22), effective tillers hill-1 (7.03), non-effective tillers hill-1 (1.19), survivor (95.1%), grains panicle-1 (106.2), grain yield (5.57 t ha-1), straw yield (6.26 t ha-1) and harvest index (0.47%) were found by transplanting 40 day old seedlings. The highest shoot weight (0.53 gm-2), 1000 grain wt. (25.3g) was found by transplanting 35 day old seedlings and 30 day old seedlings produced highest sterile spikelets (28.9) and panicle length (23.8 cm). Nitrogen rate in the nursery showed significant differences for shoot weight, root weight, survivor, plant height, total tillers hill-1, effective tillers hill-1, non-effective tillers hill-1, panicle length, grains panicle-1, grain yield and straw yield. Application of 50 kg N ha-1 gave higher plant height (108 cm) and harvest index (0.47%). On the other hand, application of 75 kg N ha-1 produced highest non–effective tillers hill-1 (1.0), grains panicle-1 (100.7), 1000 grain weight (25.3 g) and harvest index (0.47%). Application of 100 kg N ha-1 gave highest total tillers hill-1 (7.85), effective tillers hill-1 (6.85), non–effective tillers hill-1 (1.0), survivor (90.5%) and grain yield (5.01 t ha-1). Application of 125 kg N ha-1 gave highest panicle length (23.75 cm), grains panicle-1 (100.7), non–effective tillers hill-1 (1.0) and sterile spikelets (30.1). Forty day old seedlings grown with 100 kg N ha-1 at nursery found to be better in respect of grain yield. The result of the experiment also showed that aged seedlings regenerated quickly after desubmerge of water.Res. Agric., Livest. Fish.2(2): 261-269, August 2015


2015 ◽  
Vol 26 (2) ◽  
pp. 39-44 ◽  
Author(s):  
P. K. Rai ◽  
U. K. Sarker ◽  
P. C. Roy ◽  
A. K. M. S. Islam

Twenty five rice genotypes were used to study the genetic components, correlation and path coefficients during Aman season of 2011. Thirteen characters were studied to find out the suitable traits for the improvement of rice yield. Among these characters considerable correlation were observed. Correlation values of grain yield per square meter with plant height, number of tillers per hill, number of panicles per hill, panicle length, number of primary branches, number of filled grain per panicle, spikelet sterility (%), 1000 grain weight and days to flowering revealed that selection based on this traits could significantly be improved the grain yield of rice. Number of tillers per hill, number of panicles per hill, panicle length, number of filled grains per panicle, 1000-grain weight exhibited high direct effect coupled with significant positive correlation on grain yield indicating selection on the basis of these traits would enhanced yield potentiality of rice. The residual effect was found 0.179 which indicated that 82.10% of the variability was accounted for 13 yield and yield contributing traits included in the present study. Rest 17.90% variability might be controlled by other yield contributed traits that was not included in the present investigation. So direct selection based on these traits would be effective for improvement of these F4 materials


2010 ◽  
Vol 58 (3) ◽  
pp. 211-218 ◽  
Author(s):  
B. Hoffmann ◽  
N. Aranyi ◽  
M. Molnár-Láng

The safety of wheat production in Hungary requires the propagation of droughttolerant cultivars because of the regular occurrence of water deficiency. Hybridization between related species makes it possible to transfer desirable traits from one species to another. Introgression lines developed from wheat/barley hybrids were investigated together with the parental wheat and barley cultivars to determine how the added barley chromosome (segment) influences drought tolerance in wheat. The plants were grown in the field at the UP Georgikon Faculty, Keszthely. Sowing and harvest were done by hand. Half the length of the 12 m rows was covered with a plastic rain shelter on 2 nd April (EC: 30–31) to protect the plants from rain, resulting in a 163 mm difference in water supplies between the control (not covered) and stressed (covered) treatments. Data were obtained for anthesis and maturity date, plant height, root/shoot ratio, leaf water potential, grain yield and grain yield components. The plants adapted to water deficiency by increasing the root/shoot ratio and decreasing the water potential and the duration of grain filling. The grain yield was reduced by 12%, averaged over the genotypes, mainly due to a decrease in the number of spikes per plant.


2013 ◽  
Vol 20 (1) ◽  
pp. 25-32 ◽  
Author(s):  
S. H. Habib ◽  
K. M. Iftekharuddaula ◽  
M. K. Bashar ◽  
Khaleda Akter ◽  
M. K. Hossain

Forty advanced breeding lines of rice were studied during T Aman season (rainfed ecosystem) for finding out selection indices, variability and character association for grain yield and its components. All the tested characters were found showing significant variation. The highest genotypic, environmental and phenotypic variances were found in filled grains/panicle followed by plant height. High heritability associated with high genetic advance were obtained in panicles/hill, plant height, filled grains/panicle, 1000-grain weight and grain yield. Genotypic correlation coefficients were higher than the corresponding phenotypic correlation coefficients in most of the cases. Panicle length, panicles/hill and filled grains/panicle showed significant positive correlation with grain yield. Path analysis revealed that filled grains/panicle, panicles/hill and 1000-grain weight had positive and highest direct effects on grain yield. Moreover, panicle length had highest indirect effect on grain yield through filled grains/panicle. Discriminant function analysis revealed that a progressive increase in the efficiency of selection was observed with the inclusion of additional character in the selection index. Among the single variable indices, filled grains/panicle showed maximum relative efficiency over the straight selection for grain yield. The highest relative efficiency was observed with index involving seven characters, days to maturity + panicle length + panicles/hill + plant height + filled grains/panicle + 1000-grain weight + yield (t/ha). However, some of 3-traits, 4- traits, 5- traits, and 6- traits indices were also equally good.DOI: http://dx.doi.org/10.3329/bjpbg.v20i1.17015


1976 ◽  
Vol 18 (2) ◽  
pp. 217-223 ◽  
Author(s):  
R. B. Singh ◽  
G. S. Sharma

Gene action in relation to yield per plant, 1000-grain weight and number of grains per spike was studied in 9 × 9 diallel F1 and F2 populations derived separately from nine elite diverse normal and EMS treated spring wheat cultivars (Triticum aestivum L.em Thell.). Some additive and all dominance components were significant for the three characters, their relative proportions varied from character to character. Preponderance of additive gene action was revealed for 1000-grain weight, whereas prevalence of nonadditive gene action was noted for grain yield and number of grains per spike. The magnitude of the additive component increased considerably in EMS treated F2 populations for 1000-grain weight and grain yield, whereas the EMS treatment increased the proportion of nonadditive components for number of grains per spike. Breeding plans which may effectively exploit both additive and nonadditive components of variances for evolving superior breeding populations of spring wheat have been suggested.


2019 ◽  
Vol 44 (2) ◽  
pp. 253-259
Author(s):  
HZ Raihan ◽  
S Sultana ◽  
M Hoque

An experiment on combining ability was carried out with 21 crosses produced from 7×7 diallel cross without reciprocal for grain yield and yield contributing characters in maize. Analysis of variance for combining ability showed that mean square (MS) due to GCA & SCA were highly significant for all characters except GCA in plant height, cob length and 1000 grain weight and SCA in maturity and row/cob indicated that all but mentioned traits were governed by both additive and non-additive gene action. Variances due to GCA were higher for all characters except thousand grain weight revealed that the predominance of additive gene action for all characters except thousand grain weight. Parent CML 487 and Ki 21 were the best general combiner for yield and most of the yield contributing characters. Parent BMZ 57 & BMZ 15 were the best general combiner for dwarf & earliness in plant. Among all the crosses CML 473 × Ki 21, CML 487 × Ki 21 and CML 429 × BIL 182 exhibited significant positive SCA effect for grain yield. The cross CML 429 × BIL 182 may be considered as the best cross with recorded significant mean value and desired SCA for traits like 1000 grain weight, yield (t/ha), days to 50% pollen shedding, days to 50% silking, plant height, ear height and days to maturity. The promising single crosses with significant and positive SCA could be used for variety development after verifying them across locations. Bangladesh J. Agril. Res. 44(2): 253-259, June 2019


Sign in / Sign up

Export Citation Format

Share Document