The phenotypic correlation and path analysis coefficient for grain yield and its components in four local maize (Zea mays L.) genotypes

The present investigation was undertaken to estimate phenotypic correlation and path coefficient analysis for grain yield and its components in maize. Four local genotypes of yellow maize were evaluated in 2008 and 2009 growing seasons at two locations i.e. Damascus and Dir Al-Zor under three nitrogen fertilization levels (130, 195 and 260 of N. ha-1), The nitrogen fertilizer was applied at two splits. Split split plot design was used with 4 replications. Results of phenotypic correlation values showed that grain yield at Damascus location was positively and significantly associated with ear height (r= 0.204**), ear length (r= 0.205**) and number of rows per ear (r= 0.228**). On the other hand, grain yield at Dir Al-Zor location was positively and significantly associated with all studied traits at combined data whereas, it was positively and significantly associated with ear length at three levels and combined data (0.305*, 0.410**, 0.347** and 0.375**, respectively). The data of path coefficient analysis showed that ear length, ear height and number of rows per ear had positive direct effects on grain yield variation and thus grain yield improvement can be achieved through selection for ear length and ear height at Damascus location (11.06%). On the other side, data showed that each of ear height, number of kernels per row and 100-kernel weight had positive direct effects on grain yield variation (32.98%) and thus, 100-kernel weight can be considered as selection criteria may lead to the improvement of grain yield in yellow maize at Dir Al-Zor location.

The phenotypic correlation and path analysis coefficient for grain yield and its components in four local maize (Zea mays L.) genotypes

The present investigation was undertaken to estimate phenotypic correlation and path coefficient analysis for grain yield and its components in maize. Four local genotypes of yellow maize were evaluated in 2008 and 2009 growing seasons at two locations i.e. Damascus and Dir Al-Zor under three nitrogen fertilization levels (130, 195 and 260 of N. ha-1), The nitrogen fertilizer was applied at two splits. Split split plot design was used with 4 replications. Results of phenotypic correlation values showed that grain yield at Damascus location was positively and significantly associated with ear height (r= 0.204**), ear length (r= 0.205**) and number of rows per ear (r= 0.228**). On the other hand, grain yield at Dir Al-Zor location was positively and significantly associated with all studied traits at combined data whereas, it was positively and significantly associated with ear length at three levels and combined data (0.305*, 0.410**, 0.347** and 0.375**, respectively). The data of path coefficient analysis showed that ear length, ear height and number of rows per ear had positive direct effects on grain yield variation and thus grain yield improvement can be achieved through selection for ear length and ear height at Damascus location (11.06%). On the other side, data showed that each of ear height, number of kernels per row and 100-kernel weight had positive direct effects on grain yield variation (32.98%) and thus, 100-kernel weight can be considered as selection criteria may lead to the improvement of grain yield in yellow maize at Dir Al-Zor location.

Genetic Parameters of Some Quantitative Characters in Three Maize (Zea mays L.) Hybrids

Six population seeds of three yellow maize hybrids were formed at Agricultural Research Center, Homs, during 2008 and 2009 growing seasons. Their plants were evaluated in 2010. The present work aims to determine the genetic parameters in six populations (P1, P2, F1, F2, BC1, and BC2). Mean square results showed significant differences among mean values for all traits in all crosses. Significant heterosis values were positive and relative comparing to mid and better parent for most traits. The potence ratios exceeded (+1) in all traits and crosses except ear height, indicating thus over-dominance. In breeding, depression values were significant in most traits for Cross-1, while their values were non- significant in all traits for Cross-2 except plant height, and also in Cross-3 except plant height and grain yield per plant. In most traits epestasis or dominance gene action occupied the first rank in the genetic effects in order of importance to cross, with the exception of number of rows per ear, number of kernels per row and grain yield per plant where additive gene action occupied the first rank for Cross-2 and Cross-1 respectively. Therefore, it could be suggested that selection for most studied traits in the subsequent generations will be relatively more effective than in the early generations.

Genetic Analysis of Some Yield Components in Half Diallel Sweet Corn Crosses

A half diallel set of crosses among six inbred lines of sweet corn was evaluated to study heterosis and combining ability among plant height, ear height, ear diameter, number of rows per ear and ear yield per plant. The study was carried out at the agricultural research center in, GCSAR, Lattakia, Snoubar Jableh, during the 2010, 2011 seasons. Result showed that almost all crosses expressed a significant positive heterosis effect for ear yield per plant relative to mid parents and better parents; whereas, the highest positive significant percentage of heterosis for ear yield per plant were expressed by the crosses (L4xL6) which gave (198.70%, 176.81%) and (L4xL6) which gave (196.94%, 168.56%), over mid parents and better parents, respectively. The ratio (σ2GCA/σ2SCA) which was less than (1) showed that the non-additive gene action was more important than the additive gene action in all traits except plant height and ear height. The inbred lines L3 (17.061) and L4 (12.011) seemed to be the best general combiners for ear yield. Also, based on SCA effects, many of single crosses were identified as superior for ear yield, and the best hybrid was L3xL5(50.173).

The phenotypic correlation and path analysis coefficient for grain yield and its components in four local maize (Zea mays L.) genotypes

The present investigation was undertaken to estimate phenotypic correlation and path coefficient analysis for grain yield and its components in maize. Four local genotypes of yellow maize were evaluated in 2008 and 2009 growing seasons at two locations i.e.

Estimation of Combining Ability in Al-Salamoniah Maize (Zea mays L.) Hybrids for Some Quantitative Traits Under Two Dates of Nitrogen Fertilizer Application

This research aimed to evaluate the general and specific combining ability components for six inbred lines and 15 hybrids produced by a half diallel cross method, and was conducted during 2010-2011 seasons, in the Department of the Maize Researches at G.C.S.A.R. Damascus . The evaluation included the grain yield, ear height, ear length, and silking under two different treatments of nitrogen fertilizer (1- addition of 50% of N-fertilizer with sowing and the other 50% one month after sowing. 2- addition of 50% of N-fertilizer 18 days after sowing and 50% one month after sowing).and 3 replicates. Results indicated that: Mean squares of inbred lines, and hybrids were highly significant for all studied traits under two adding dates of nitrogen fertilizer, which indicated the presence of genetic distance among parental lines. The ratios (
2 GCA/
2 SCA) showed that additive gene effect was more important than non-additive gene effect in controlling all studied traits except grain yield which showed dominance of non-additive gene effect under tow dates. Many of significant positive GCA effects were obtained for all traits, therefore, it could be concluded, that the inbred lines CML.330, IL.26-09 and CML.334 seemed to be the best general combiners for grain yield. The hybrid (CML.368 × IL.215-09) had showed the best specific combining ability effects for grain yield under the first date, while the hybrid (CML.330 × IL.26-09) showed the best SCA effects under the second date. The second adding date of nitrogen fertilizer (50% 18 days after sowing and 50% one month after sowing) had surpassed of the first date (50% with sowing and 50% one month after) with significant effects for grain yield trait.

Genetic behavior for some quantitative traits in a hybrid of durum wheat

This study was carried out at Karahta station, Department of Field Ccrops researches, General Commission for Scientific Agriculture Researches (GCSAR), Damascus Country Side, Syria during the 2009-2010and 2010-2011 growing seasons to estimate gene action for grain yield and its components. Seeds of the durum wheat hybrid (Sham5 X Azgar1) were grown in three replicates. Results indicated that the used genotypes had good variation to be used as parents in wheat hybridization program to achieve significant genetic advance. Mean square results showed significant differences among mean values of the five populations for all studied traits in the hybrid and in most traits, epistasis or dominance gene action occupied the first rank to the genetic effects. It was suggested that selection for most studied traits in the subsequent generations is relatively more effective than in early generations.

Genetic relationships for yield and its components in durum wheat

This study was carried out at Karahta Station, Dept. of Field Crops Researches, General Commission for Scientific Agriculture Researches (GCSAR) Damascus, Syria, during the growing seasons (2009-2010, 2010-2011). The crosses were grown inatrial using randomized complete block design (RCBD) with three replicates in order to evaluate number of spikes per plant, number of grains per spike, thousand kernel weight and grain yield per plant and estimate some genetic indices: broad scenes heritability (BSH), narrow scenes heritability (NSH), and genetic advance (GA). Seeds of five populations of the three evaluated single hybrids were formed by crossing of five inbred lines. Analysis of variance results showed significant differences among mean values of the five populations of each cross for all studied traits. The results revealed that the broad scenes heritability ranged between high and moderate for the following productivity traits (SP/PL, GR/SP, TKW and GY/P) and it was (75, 40, 57) (38, 80, 38) (74, 60, 85) and (73, 73, 71) for the three crosses, respectively. Additive gene action noticed on most traits indicated less selection cycles to improve these traits.

Estimation of statistical genetic parameters and heritability for oil, protein and yield traits in soybean hybrids (Glycine max (L.) Merr.)

The present study was conducted at the First of May Station belongs to the General Commission For Scientific Agricultural Research (GCSAR) at Damascus during 2011 and 2012 growing seasons to estimate gene action, heritability, genotypic and phenotypic coefficient variations (GCV, PCV) and genetic advance for two crosses of soybean. The five population (P1, P2, F1, F2, F3) of each cross were grown in a randomized complete block design (RCBD) with three replications in order to evaluate oil and protein contents and seed yield traits. Results of mean square analysis showed significant differences (p<0.05) among mean values of the five populations for all studied traits between the populations of each cross. The second cross achieved high broad and narrow sense heritability (66%, 44%) for protein content, high value of phenotypic and genotypic variations in seed yield in the second cross achieved (18.03,17.30) and high value of expected genetic advance was obtained 11.09%. In most traits, epistasis of the dominance × dominance type of gene action occupied the first rank in order of importance in controlling inheritance of the evaluate traits in both crosses indicating the importance of selection in late segregating generations to improve these traits. These findings are supported by high values of heritability, which was related with low to moderate expected genetic advance in two crosses.

Inheritance of some quantitative characters in durum wheat

This study was carried out at Karahta station of field crops research department General Commission for Scientific Agriculture Researches (G.C.S.A.R.) Damascus Syria during the 2009 -2010 and 2010 -2011 growing seasons to estimate gene action, potency ratios, heterosis and Inbreeding depressions. Five population seeds of two single hybrids (Cham-5 × Azeghar-1), (Bohoth-5 × Gidara-2) were formed by crossing of four inbred lines. The crosses were subjected to randomized complete block design (RCBD) with three replications in order to evaluate plant height (PH), number of grains per spike (GRSP), flag leaf area (FLA), thousand kernel weight (TKY) and grain (p<0.05) yield per plant (GYP). Mean square results showed significant differences among mean values of the five populations for all studied traits in all crosses. Significant heterosis values compared to mid and better parent were observed for all traits with exception of (PH) (5.82, 1.62)%, (GRSP) (27.49 9.66)% and(TKY) (3.05 7.53)% for Cross-1. (GYP) (82.46, 96.63)% for Cross- 2. (GRSP) (9.09 5.14)%. The potency ratios exceeded (+1) in all traits and crosses except (PH) (-2.23) for Cross-2. Indicating that over-dominance towards low placement. The results indicated that Inbreeding depression values were significant for all traits in Cross-1 except for (GRSP) (10.33), and (TKY) (15.23). While its values were non- significant for all traits inCross-2except (GRSP) (25.46*). In most traits epestasis or dominant gene action occupied the first rank in controlling these traits in both crosses. It could be suggested that selection for most studied traits in the subsequent generations will be relatively more effective than in early generations.