scholarly journals Combining ability of tropical maize cultivars in organic and conventional production systems

2011 ◽  
Vol 41 (5) ◽  
pp. 739-745 ◽  
Author(s):  
Lucimar Rodrigues de Oliveira ◽  
Glauco Vieira Miranda ◽  
Rodrigo Oliveira DeLima ◽  
Leandro Vagno de Souza ◽  
João Carlos Cardoso Galvão ◽  
...  
Keyword(s):  
Grain Yield ◽  
Combining Ability ◽  
Production Systems ◽  
General Combining Ability ◽  
Genetic Effects ◽  
Organic Production ◽  
Maize Germplasm ◽  
Maize Cultivars ◽  
Significant Difference ◽  
Conventional Production

The objectives were to identify maize germplasm for the organic productions system and to compare the genetic effects of the grain yield of maize cultivars in organic and conventional production systems. Diallel crosses were made between six maize cultivars and the hybrid combinations were evaluated in conventional and organic production systems. The hybrid combinations produced different grain yields in the two production systems. The interaction between general combining ability and production systems was significant for grain yield, ear height and number of ears. This indicates that the additive genetic effects differ in organic and conventional production systems. The specific combining abilities (SCA) were significant for grain yield and plant height, indicating a significant difference between the non-additive effects. However, the SCA x production systems interactions were not significant for those traits. It was concluded that for the development of maize cultivars for the organic production system, selection must be made in the specific environment for the expression of favorable alleles that confer advantages for adapting to this system; the general combining ability of genitors is different for the two production systems, but the specific combining ability isn't different in organic and conventional systems.

scholarly journals Combining ability of maize grain yield under different levels of environmental stress

2009 ◽  
Vol 44 (10) ◽  
pp. 1297-1303 ◽  
Author(s):  
Leandro Vagno de Souza ◽  
Glauco Vieira Miranda ◽  
João Carlos Cardoso Galvão ◽  
Lauro José Moreira Guimarães ◽  
Izabel Cristina dos Santos
Keyword(s):  
Environmental Stress ◽  
Grain Yield ◽  
Combining Ability ◽  
Genetic Effects ◽  
Tropical Maize ◽  
Maize Grain Yield ◽  
Maize Cultivars ◽  
Stress Environments ◽  
Maize Grain ◽  
Different Levels

The objectives of this work were to caracterize the tropical maize germplasm and to compare the combining abilities of maize grain yield under different levels of environmental stress. A diallel was performed among tropical maize cultivars with wide adaptability, whose hybrid combinations were evaluated in two sowing dates, in two years. The significance of the environmental effect emphasized the environmental contrasts. Based on grain yield, the environments were classified as favorable (8,331 kg ha-1), low stress (6,637 kg ha-1), high stress (5,495 kg ha-1), and intense stress (2,443 kg ha-1). None of the genetic effects were significant in favorable and intense stress environments, indicating that there was low germplasm variability under these conditions. In low and high stresses, the specific combining ability effects (SCA) were significant, showing that the nonadditive genetic effects were the most important, and that it is possible to select parent pairs with breeding potential. SCA and grain yield showed significant correlations only between the closer environment pairs like favorable/low stress and high/intense stress. The genetic control of grain yield differed under contrasting stress environments for which maize cultivars with wide adaptability are not adequate.

scholarly journals Association between Griffing's diallel and the adaptability and stability of Eberhart and Russel

1999 ◽  
Vol 22 (3) ◽  
pp. 451-456 ◽  
Author(s):  
Cleso Antônio Patto Pacheco ◽  
Cosme Damião Cruz ◽  
Manoel Xavier dos Santos
Keyword(s):  
Combining Ability ◽  
General Combining Ability ◽  
Genetic Effects ◽  
Specific Combining Ability ◽  
Regression Coefficients ◽  
Stability Parameters ◽  
The Mean ◽  
Additive Genetic Effects ◽  
F1 Cross

The objective of the present work was to provide a methodology to study the inheritance of adaptability and stability through the breakdown of Eberhart and Russell regression coefficients and regression deviations in effects due to the mean and additive genetic effects (gi's and gj's) as well as dominance effects (sij's) of Griffing´s methodology, when the diallel is conducted in several environments. It was concluded that the adaptability and stability parameters are determined in the same manner as are genetic effects. So an F1 cross inherits half the general combining ability (GCA) mean effect from each parent, while the effects due to specific combining ability (SCA) are subjected to the same considerations relative to sij's, i.e., they are dependent on specific combinations.

scholarly journals Diallelic analysis for lysine and oil contents in maize grains

2009 ◽  
Vol 66 (2) ◽  
pp. 204-209 ◽  
Author(s):  
Leonardo Oliveira Medici ◽  
Salete Aparecida Gaziola ◽  
Vanderlei Aparecido Varisi ◽  
José Antonio Carmezini de Paula ◽  
Renato Rodrigues Ferreira ◽  
...  
Keyword(s):  
Grain Yield ◽  
Combining Ability ◽  
Oil Content ◽  
General Combining Ability ◽  
Lysine Content ◽  
Nitrogen Levels ◽  
N Level ◽  
Complete Series ◽  
Selection For ◽  
Selection Of

Six S5 lines of maize, with differences for lysine and oil contents in grains, were used to carry out a complete series of diallelic crosses. The resulting 15 hybrids were grown in a field at two nitrogen levels (10 and 130 kg N ha-1). The general combining ability (GCA) and specific combining ability (SCA) were obtained by using the method 4, model I of Griffing for grain yield, and grain lysine and oil contents. Significant (p < 0.001) interaction was observed between GCA and N levels for grain yield, indicating the selection of different lines for each N level. This interaction was not significant for lysine content, but there were significant effects of GCA for this trait at both N levels (p < 0.1). Significant effects were not observed for GCA or SCA for oil content, however a positive correlation was observed between lysine and oil contents in the hybrids, in the lines and even in the control cultivars. The results indicate the effectiveness of selection for lysine content, irrespective of N level, in the studied non-opaque maize lines, and the possibility of achieving both high lysine and oil content in grains.

Welfare assessment of conventional and organic broilers in Denmark, with emphasis on leg health

2018 ◽  
Vol 183 (6) ◽  
pp. 192-192 ◽  
Author(s):  
Fernanda M Tahamtani ◽  
Lena K Hinrichsen ◽  
Anja B Riber
Keyword(s):  
Contact Dermatitis ◽  
Broiler Chickens ◽  
Production Systems ◽  
Organic Production ◽  
Walking Ability ◽  
Welfare Assessment ◽  
Welfare Indicators ◽  
Tibial Dyschondroplasia ◽  
Conventional Production ◽  
Gait Score

The aim of this study was to survey and report the walking ability in broilers housed in both conventional and organic production systems in Denmark. To this end, the authors assessed the walking ability, by using the Bristol scale, in 31 conventional broiler flocks and in 29 organic broiler flocks distributed across Denmark. In addition, assessment of contact dermatitis, leg abnormalities, scratches and plumage cleanliness, as well as postmortem analysis of tibial dyschondroplasia, was performed in conventional broilers. The survey found a prevalence of 77.4 per cent of impaired walking ability (gait score (GS) >0) in conventional broilers and 38.1 per cent in organic broilers. The prevalence of severe lameness (GS >2) was 5.5 per cent and 2.5 per cent for conventional and organic broilers, respectively. The prevalence of tibial dyschondroplasia in conventional broilers was 4.7 per cent. The results on other welfare indicators are also presented for conventional broilers. The results from the present and previous surveys indicate that the prevalence of impaired walking ability in broiler chickens in the Danish conventional production system is high, but the severity has been steadily decreasing over the last 19 years. Furthermore, the results from the survey of organic broilers suggest that lameness is less prevalent and severe in this system relative to conventional production.

Combining ability and heterosis studyin maize inbreds throughout diallel mating design

2018 ◽  
Vol 43 (4) ◽  
pp. 599-609
Author(s):  
ANMS Karim ◽  
S Ahmed ◽  
AH Akhi ◽  
MZA Talukder ◽  
A Karim
Keyword(s):  
Grain Yield ◽  
Plant Height ◽  
Combining Ability ◽  
Gene Action ◽  
General Combining Ability ◽  
Specific Combining Ability ◽  
Gene Effects ◽  
Additive Type ◽  
Additive Gene ◽  
Ear Height

Combining ability effects were estimated for grain yield and some other important agronomic traits of maize in a 7×7 diallel analysis excluding reciprocals. The variances for general combining ability (GCA) were found significant for yield, days to pollen shedding, days to silking and ear height while it was found non-significant for plant height and number of kernels/ear. Non-significant general combining ability (GCA) variance for plant height and number of kernels/ear indicates that these two traits were predominantly controlled by non- additive type of gene action. Specific combining ability (SCA) was significant for all the characters except yield and days to silking. Non-significant specific combining ability (SCA) variance for yield and days to silking suggests that these two traits were predominantly controlled by additive type of gene action. Both GCA and SCA variances were found significant only in days to pollen shedding and ear height indicated the presence of additive as well as non additive gene effects for controlling the traits. However, relative magnitude of these variances indicated that additive gene effects were more prominent for all the characters studied except days to silking. Parent BIL95 was the best general combiner for both high yield and number of kernels/ear and parent BML4 for dwarf plant type. Two crosses (BML4× BML36 and BIL114× BIL31) exhibited significant and positive SCA effects for grain yield involved low × average and average × average general combining parents. The range of heterosis expressed by different crosses for grain yield and days to silking was from -65.83 to 21.26 percent and -17.85 to 8.22 percent, respectively.. The better performing three crosses (BIL114×BIL31, BIL138×BIL95 and BIL31×BIL95) can be utilized for developing high yielding hybrid varieties as well as for exploiting hybrid vigour.Bangladesh J. Agril. Res. 43(4): 599-609, December 2018

scholarly journals Evaluation of inbred lines of maize (Zea mays L.) through line × tester method

2015 ◽  
Vol 39 (4) ◽  
pp. 675-683
Author(s):  
MN Amin ◽  
M Amiruzzaman ◽  
A Ahmed ◽  
MR Ali
Keyword(s):  
Zea Mays ◽  
Grain Yield ◽  
Combining Ability ◽  
Zea Mays L ◽  
Gene Action ◽  
Inbred Lines ◽  
General Combining Ability ◽  
Genotypic Differences ◽  
Mean Values ◽  
Wide Range

Maize inbred lines were evaluated by using line × tester method involving 11 lines and 3 testers for grain yield and its components through estimation of general combining ability (gca) and specific combining ability (sca) effects. Highly significant genotypic differences were observed indicated wide range of variability present among the genotypes. The crosses with high sca effect for grain yield were evolved from high × low general combiner parents which reveled additive × dominance type of gene action. The cross combinations 9MS4-1 × L22, 9MS4-1 × L486, 9MS4-2 × L431, 9MS4-11 × L486 and 9MS4- 15 × L431 with high positive sca effect having high mean values might be used for obtaining high yielding hybrids. The information on the nature of gene action with respective variety and characters might be used depending on the breeding objectives. DOI: http://dx.doi.org/10.3329/bjar.v39i4.22547 Bangladesh J. Agril. Res. 39(4): 675-683, December 2014

COMPARISON OF MICROBIOLOGICAL QUALITY OF MILK PRODUCTS FROM ORGANIC AND CONVENTIONAL PRODUCTION

2018 ◽  
Vol XX (6) ◽  
pp. 147-153
Author(s):  
Anita Kukułowicz
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Dairy Product ◽  
Microbiological Quality ◽  
Organic Production ◽  
Microbiological Analysis ◽  
Milk Products ◽  
Significant Difference ◽  
Conventional Production

The aim of the research was to compare the microbiological quality of dairy products derived from organic and conventional farming. The test material consisted of milk and milk products (natural yoghurt, cream, curd cheese, rennet ripening cheese, milk). Investigated products were subjected to microbiological analysis and marked for the number of Enterococcus sp., Staphylococcus aureus, yeast and moulds, Escherichia coli as well as to state the presence of Salmonella sp. in them. All samples were free of Salmonella sp. Escherichia coli occurred in 2 samples of curd cheese from organic production. Products derived from organic and conventional production didn’t differ in the average number of microorganisms depending on the type of dairy product, with the exception of ripening rennet cheese, which showed a significant difference in the amount of Staphylococcus aureus.

Heterosis and combining ability in hybrids ofAvena sativaL. andA. byzantinaC. Koch.

1969 ◽  
Vol 72 (1) ◽  
pp. 85-92 ◽  
Author(s):  
G. Jenkins
Keyword(s):  
South Africa ◽  
Grain Size ◽  
Grain Yield ◽  
Combining Ability ◽  
Unit Area ◽  
General Combining Ability ◽  
European Origin ◽  
Straw Yield ◽  
North West ◽  
Yield Trial

SUMMARYThree varieties ofAvena byzantinaC. Koch., Sierra, Avon and Anita, originating respectively in California, Australia and South Africa, together with the Dutch variety Condor (A. sativaL.) were used as ‘subject’ varieties in crosses with a range of nine tester varieties of mainly north-west European origin. The results of a yield trial of spacedF1transplants and a drilledF2trial are presented.In theF1trial there was marked heterosis for grain yield, the thirty-six crosses yielding, on average, 109 % of the higher yielding parent, with individual cross values ranging from 68 to 139%. Heterosis was more marked insativa × byzantinacrosses than insativa × sativacrosses and the variety Sierra showed particularly high general combining ability. In theF2trial, heterosis was considerably reduced and the thirty-six crosses yielded, on average, only 96% of the higher yielding parent. In someF1crosses, heterosis for grain yield was accompanied by transgression of the higher yielding parent in number of panicles per unit area. The number of grains per panicle was positively correlated with grain yield in theF2trial but no heterosis was observed for this component. Grain size was negatively correlated with yield in theF2trial and heterosis for this component was observed in a few crosses in which yield heterosis occurred.Straw height was positively correlated with grain yield in theF1trial but negatively correlated in theF2trial. Crosses showing heterosis for yield exceeded the mid-parent but not the taller parent in straw height. The ratio of grain yield to straw yield was higher for the progenies of thebyzantinavarieties Sierra and Avon than for the progenies of thesativasubject Condor. Grain yield was positively correlated with number of days to 50% panicle emergence in both trials.It is concluded that theA. byzantinavarieties Sierra and Avon could, with advantage, be used for hybridization with adapted genotypes ofA. sativa, thereby enlarging the gene pool available to oat breeders in north-west Europe.

Optimal seeding rate for organic production of lentil in the northern Great Plains

2009 ◽  
Vol 89 (6) ◽  
pp. 1089-1097 ◽  
Author(s):  
J M Baird ◽  
S J Shirtliffe ◽  
F L Walley
Keyword(s):  
Great Plains ◽  
Plant Density ◽  
Production Systems ◽  
Organic Production ◽  
Weed Suppression ◽  
Northern Great Plains ◽  
Seeding Rate ◽  
Nitrogen And Phosphorus ◽  
Economic Return ◽  
Conventional Production

Organic lentil (Lens culinaris Medik.) producers must rely upon the recommended rate for conventional production of 130 plants m-2, but this seeding rate may not be suitable, as organic and conventional production systems differ in management and inputs. The objective of this study was to determine an optimal seeding rate for organic production of lentil considering a number of factors, including yield, weed suppression, soil nitrogen and phosphorus concentrations, plant uptake of phosphorus, and economic return. A field experiment was conducted for 4 site-years at locations near Saskatoon, SK. Treatments included seeding rates of 15, 38, 94, 235 and 375 seeds m-2. Seed yield increased with increasing seeding rate up to 1290 kg ha-1. Weed biomass was reduced by 59% at the highest seeding rate as compared with the lowest seeding rate. Post-harvest soil phosphorus and nitrogen levels were similar between seeding rate treatments. Economic return was maximized at $952 ha-1 at the highest density of 229 plants m-2, achieved with a seeding rate of 375 seeds m-2. Organic farmers should increase the seeding rate of lentil to achieve a plant density of 229 plants m-2 to increase profitability and provide better weed suppression.Key words: Lentil, organic, seeding rate, weed suppression, economic return

scholarly journals Combining ability studies for yield, associated traits and quality attributes in rice for South Gujarat (Oryza sativa L.)

2017 ◽  
Vol 9 (1) ◽  
pp. 60-67
Author(s):  
Navin Chander Gahtyari ◽  
P. I. Patel ◽  
Rakesh Choudhary ◽  
Sudhir Kumar ◽  
Naveen Kumar ◽  
...  
Keyword(s):  
Oryza Sativa ◽  
Grain Yield ◽  
Plant Height ◽  
Combining Ability ◽  
Amylose Content ◽  
Oryza Sativa L ◽  
Block Design ◽  
General Combining Ability ◽  
Specific Combining Ability ◽  
Kernel Length

Line x tester analysis using a set of four females, ten males and their forty hybrids was carried out to esti-mate the general combining ability of parents and specific combining ability of hybrids for yield and ten other associ-ated components in rice (Oryza sativa L.) in a Randomized Block Design during Kharif 2011. GCA variances for females (s2f) were significant at 0.1% level of significance for plant height (40.8), no. of grains per panicle (505.9), grain yield per plant (29.1), test weight(17.9), straw yield per plant (61.3) and kernel L/B ratio (0.2) whereas specific combining ability (SCA) variances for f x m interactions were highly significant for all the characters. Non-additive gene action was prevalent in all characters (Range: 0.03 in amylose content to 0.88 in kernel length breadth ratio) except plant height (1.33) as evident by low GCA to SCA ratio. None of the parents were good general combiner for all traits, however, female IR-28 and male AMT-119 and PNR-546 were good general combiners for a maximum number of traits i.e. five traits out of eleven.. The general combining ability for grain yield per plant for female parent Gurjari (6.19) and NVSR-178 (5.29); and male parents AMT 119 (2.73) and PNR 546 (2.44) makes them a good choice for improving yields in a hybridization programme as these female and male parents are also having signifi-cant GCA effects for maximum number of yield associated traits i.e. four and five traits out of eleven for female and male parents respectively. A vis-à-vis comparison of top three specific combining ability crosses with their mean performance showed correlation and these crosses were having at least one good general combining ability parent.

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