Molecular and Phenotypic Evaluation of some Summer Squash Inbred Lines

Abstract

In order to evaluate molecular and phenotypic diversity and detecting molecular markers for six summer squash inbred lines belong to species [Cucurbita pepo L.], five RAPD and five ISSR primers were used as well as 12 economical traits were estimated. These primers succeeded in generating reproducible and reliable amplicons. RAPD revealed 88.1 % of polymorphism while ISSR techniques showed 80.5% polymorphism. The resolving power (Rp) value for RAPD technique was 5.00 which was higher than 3.40 of ISSR technique. Therefore, the RAPD technique was better than ISSR technique in evaluated molecular diversity and discrimination capacity among lines. But, the ISSR technique was better than RAPD technique in showing unique markers (21 for ISSRs and 9 for RAPDs). Also, the correlation between phenotypic distance (PD) and molecular distance (MD) based on ISSRs was 0.173 highest than with MD based on RAPDs (0.045). On the other hand, with the exception of P6 which gave significant desirable value in two traits (number of fruits and yield per plant), each of the other five strains gave a significant desirable value in one trait, thus the number of these traits which distinguished in the six inbred lines were 7 traits. These traits could be linked with all unique markers detected in this study. The inbred line P5 showed the highest number of unique markers (10, 9 of them were positive), one or some of which may be linked with NL trait that showed in this inbred line a significant desirable value. Followed by the inbred line P6 which showed seven unique markers (six of them were positive) one or some of which may be linked with NF and/or Y/P traits. This indicated that some of these markers may be used as markers assisting selection in the breeding and improvement of squash.

Molecular and phytochemical assessment for some seedy strains of Alamar apricot rootstock under salinity stress

“…On the other hand, by calculating the correlation coefficients among Euclidian distances and molecular distances based on ISSR, SCoT and combined data, significant positive correlation was found only between distances based on ISSR data and Euclidian distances (r = 0.476). This indicates that the ISSR markers in Table 1, through other studies can be associated with the traits of interest (such as salinity stress-related traits) according to Abd El-Hadi et al [45]. Especially, the unique markers which identified for A3 seedy strain that showed best performance in terms of all tested stress-related parameters.…”

“…DNA profiling ( Figures S2 and S3, supplementary data) showed that ISSR primers except 14A generated 17 (10 negative and 7 positive) out of 77 amplicons, also SCoT primers except SCoT-2 generated 23 (15 negative and 8 positive) out of 101 amplicons. These unique amplicons may be useful as unique markers as explained by Adhikari et al [32], in Cymbopogon; Abd El-Aziz and Habiba [43], in canolla; Abd El-Aziz et al [44], in tomato and Abd El-Hadi et al [45] Figure 1. Banding patterns of ISSR-PCR products for eight seedy strains of Alamar apricot rootstock produced with seven primers.…”

“…Also, showed highly significant positive correlation among ISSR and SCoT with the combined data (r = 0.62 and 0.89, respectively), this matches with Xanthopoulou et al [48], in squash. So, cluster analysis was conducted using combined data only, according to Abd EL-Aziz et al [44], and Abd El-Hadi et al [45]. Figure 3 shows dendrogram of the AHC analysis derived from UPGMA method using Dicedissimilarity index for combined data of ISSR and Table 1.…”

Assessment of Genetic Diversity in Summer Squash Genotypes Using some Yield Traits and DNA Markers Analysis under Sinai Conditions

“…According to Egyptian Ministry of Agriculture and Land Reclamation, the total production area of squash in 2016 was 73558 fed and produced 551023 tons of fruits (Nassar et al, 2019). At the same time, it is considered an important source of human food, many nutrients, and medicinal uses (Matlob et al, 1989;Abd El-Hadi et al, 2017). The low production of summer squash in some production regions due to the deficiency in fruit setting resulted from unfavorable sex expression and bad crosspollination flowers due to short blooming period (Albrifcany, 2015).…”

“…Inconsistent genotypic responses to environmental factors from location to location, is a function of G × E interaction, hence resulting in alteration to the ordering of genotypes from one environment to another. Lately, plant breeders utilized modern methods such as molecular marker to evaluate genetic variability (Abd El-Hadi et al, 2017). DNA fingerprinting is an indispensable tool towards tracing of lineages in plant lines.…”