ESTIMATING THE GENETIC PARAMETERS OF YIELD AND YIELD COMPONENT TRAITS IN SQUASH (Cucurbita pepo, L.)

Abstract

The main objective of this investigation was to determine the genetic parameters, heritability in both broad and narrow senses, combining abilities and correlation for yield and yield component traits in squash (Cucurbita pepo, L.). For this purpose, five squash varieties were used .These varieties were: Eskandrani (P1); Zucchino tondo di piacenza (P2); Black beouty (P3); Zucchino romanesco (P4) and Coppi (P5). During the summer season of 2011, acomplete diallel crosses mating design was made to evaluate the performances of the 20 F1 hybrids including the reciprocal will their five parental varieties in afield trial at the Experimental Station, Faculty of Agriculture, Mansoura University. Data were recorded on the following traits, number of fruitsper plant (No.F./P.), fruits yield per plant (F.Y./P.Kg), fruit length (F.L.cm), fruit diameter (F.D.cm) and fruit shape index (F.Sh.I). The results indicated that the mean squares for all genotypes were highly significant for all yield and yield component traits. The results of means showed that Eskandrani (P1) was the highest parent for Number of fruits per plant No.F./P. the parental variety Zucchino romanesco (P4) was the highest variety for F.L.cm and F.Sh.I. However, the highest F1 hybrid for fruit yield per plant was Eskandrani (P1) × Zucchino tondo di piacenza (P2) with the mean value of 11.24 kg. Whereas, the highest F1r hybrid was Zucchino romanesco (P4) × Eskandrani (P1) with the mean value of 10.51 kg. The results revealed that the GCA effects (gi) were highly significant for the two parents: Eskandrani (P1) and Zucchino romanesco (P4) for F.L.cm, F.D.cm and F.Sh.I traits. At the same time, the results also revealed that the GCA effects were highly significant for the parents: Zucchino tondo di Piacenza (P2) for F.L.cm and F.D.cm; Black beouty (P3) for F.D.cm and F.Sh.I and Coppi (P5) for F.Sh.I. The results indicated the importance of both (GCA) and (SCA) combining abilities. General combining abilities (GCA) were larger than specific combining abilities (SCA) for all yield and yield component traits except fruits yield per plant (F.Y./P.Kg). The estimates of heritability in broad sense (h 2 b) were larger in magnitudes than those of narrow sense (h 2 n) for all studied traits. The values of heritabilities in broad sense ranged from0.513 to 0.894 for yield and yield component traits.

Heterosis and Genetic Behavior of Some Yield and Yield Component Traits in Squash (Cucurbita pepo, L.)

“…P 1 , P 2 and P 4 seemed to be the best combiners for F.Y./P.kg. These results were in agreement with the results obtained by Abd El-Hadi et al, (2004); Abdein (2005); Al-Ballat 2008; Pradip et al, (2013) and Sanin et al, (2014).…”

“…These results were in agreement with the results obtained by Abd El-Hadi et al, (2001); Abd El-Hadi et al, (2004); Iathet and Piluek (2006); Al-Araby, (2010); Thangamani, et al, (2011); Jahan et al, (2012) and Marie et al, (2012).…”

“…It was obtained that some F 1 and F 1r (reciprocal) hybrids for yield and yield component traits exceeded the better parent and naturally exceed versus the midparents. Similar results were obtained by Abd El-Hadi et al, (2001); Abd El-Hadi et al, (2004); Iathet and Piluek (2006); Al-Araby, (2010); Thangamani et al, (2011); Jahan et al, (2012) and Marie et al, (2012).…”

“…The manifestations of heterosis as well as the nature of gene action were studied in squash by many authors among them Gabr (2003), Abd El-Hadi et al, (2004), Abdein (2005), Al-Ballat (2008) and Al-Araby (2010). They estimated heterosis for yield and some economical traits in squash.…”

Pumpkin (Cucurbita spp.): A Crop to Mitigate Food and Nutritional Challenges

“…The results also showed that the degrees of heterosis vs. mid parents had really significant values for the majority of the variables studied, and the projections of heterosis vs. the better parent were highly significant for the majority of the variables studied. Although some hybrids showed significant heterosis for some variables, none of the hybrids demonstrated increased heterosis for all variables and preferable heterosis over the mid and better parents [162]. Heterosis breeding allows for a one-generation enhancement in yield and other desirable traits that would be more time consuming and difficult to achieve with other traditional breeding procedures [163].…”