Watermelon (Citrullus lanatus) is a popular crop worldwide. Compared to diploid seeded watermelon, triploid seedless watermelon cultivars are in great demand. Grafting in triploid and tetraploid watermelon produces few seedlings. To learn more about how genome duplication affects graft compatibility, we compared the transcriptomes of tetraploid and diploid watermelons grafted on squash rootstock using a splicing technique. WGCNA was used to compare the expression of differentially expressed genes (DEGs) between diploid and tetraploid watermelon grafted seedlings at 0, 3, and 15 days after grafting (DAG). Only four gene networks/modules correlated significantly with phenotypic characteristics. We found 11 genes implicated in hormone, AOX, and starch metabolism in these modules based on intramodular significance and RT-qPCR. Among these genes, two were linked with IAA (r2 = 0.81), one with ZR (r2 = 0.85) and one with POD (r2 = 0.74). In the MElightsteelblue1 module, Cla97C11G224830 gene was linked with CAT (r2 = 0.81). Two genes from the MEivory module, Cla97C07G139710 and Cla97C04G077300, were highly linked with SOD (r2 = 0.72). Cla97C01G023850 and Cla97C01G006680 from the MEdarkolivegreen module were associated with sugars and starch (r2 = 0.87). Tetraploid grafted seedlings had higher survival rates and hormone, AOX, sugar, and starch levels than diploids. We believe that compatibility is a complicated issue that requires further molecular research. We found that genome duplication dramatically altered gene expression in the grafted plants’ IAA and ZR signal transduction pathways and AOX biosynthesis pathways, regulating hormone levels and improving plant survival.

Watermelon is one of the most desirable vegetable crops in the world. Recently, grafting is common in watermelons worldwide, but not all grafting methods are compatible with polyploids. In this study, diploid, triploid, and tetraploid from one watermelon variety, “Mi Mei”, were grafted on the “Xijiaqiangsheng” squash rootstock to study the effect of genome duplication on graft compatibility. Three grafting methods (splice, hole, and tongue) were used to determine graft compatibility. Significant differences in survival rates, hormones, antioxidants (AOX), sugars, and starch contents were observed between compatible/incompatible combinations. Compatible combinations with high survival rates showed high levels of hormones, AOX, carbohydrates, and low hydrogen peroxide H2O2 compared to incompatible plants. The hole grafting method was more efficient with diploid, while splice was efficient with a tetraploid, and both methods can be used for triploid. Compatibility is a combined effect of hormone, carbohydrate, and antioxidant activities. We predict that compatibility is a complex process and that further molecular studies must be performed to dig deep into this phenomenon.

Climate changes are critical global challenges limiting crop development and productivity. Plant breeding is an exceptional solution for providing thermotolerant genotypes. Plant breeding efficiently is a unique solution for providing food security worldwide. The germplasm genetic diversity of cucumber parental lines should support the release of new hybrids. In this study, A half-diallel design mating was performed with six parental cucumber lines to produce 15 hybrids under heat stress conditions in 2019. In 2020 and 2021, all genotypes were evaluated under heat stress conditions, using a randomized complete block design. The analysis of variances revealed significant differences among all genotypes. The mean performance showed that the hybrid, Parent 1×Parent 2 (P1× P2) was the superior hybrid, followed by Parent 1 (P1) for growth and yield components. The descriptive evaluation adequately demonstrated the greatest variation among all genotypes. The genetic distance between parental lines was divided into two groups based on their genetic bases. General combining ability (GCA), specific combining ability (SCA), and heterosis results revealed that P1 and P2 exhibited the highest effects of GCA in the desirable direction for vegetative, yield, and earliness traits. However, P3 showed the highest effect on most fruit traits. According to SCA effects and heterosis, the hybrids P1×P2, P1×P3, and P2×P5 demonstrated superiority in most traits. The selective parents were the good combiners by accumulative selective genes, which could be valuable in hybridization to produce new various prospective hybrids.

Vegetable breeding is one of the most important ways to ensure food security. The current study was conducted on five inbred lines to obtain 10 F1 pickling cucumber hybrids using half diallel mating design. The results indicated that high significant differences between all genotypes compared with check in all studied traits. In addition to, significant general (GCA) and specific combining ability (SCA) effects for all studied traits. The ratio GCA / SCA was less than unity, which indicates that the non-additive genetic variance component. Furthermore, some genetic parameters were revealed that two parents (P5 and P2) were good general combiners for most traits. The five crosses (P1 × P3), (P1 × P4), (P3 × P4), (P3 × P5), and (P4 × P5) exhibited significant desirable positive SCA in all commercial traits which effective on economic productivity. Most of these hybrids gave significant heterosis values over mid and high parents in vegetative, flowering, early, and total yield characteristics. Generally, the parent (P5) could be used as a promising progenitor for all commercial traits in addition to genetic improvements by hybridization.

The main objective of this study was to maximize productivity per unit area for cabbage and lettuce crops using the intercropping system and increase its efficiency with biofertilizers. The study compared a monocropping with an intercropping system in combination with bio-fertilization to improve growth, yield, soil efficiency, water efficiency, and reduce chemical residual impacts on the soil. In the two winter, seasons of 2019 and 2020, three fertilizer treatments,100% recommended mineral fertilization (RMF), arbuscular mycorrhizal fungi (AMF), and mixed treatment (AMF and 50% RMF) were conducted in monocropping and intercropping systems for cabbage and lettuce. The experiments were done in a factorial randomized complete block designed. The results revealed no significant differences between mono and intercropped systems for most horticultural traits in two seasons, except for the head length and diameter of cabbage that were affected by the intercropping system. The mixed treatment supported the intercropping system to outperform all treatments. The mixed treatment recorded the highest horticultural parameter values and the most improvement of mineral uptake, potential of hydrogen (pH), total dissolved solids (TDS), and enzyme activities in plants and soil, as well as an economical use efficiency for yield, water, and soil. The results demonstrated the effectiveness of the intercropping system with biofertilizers in producing a high yield of crops while also preserving biological balance of soil, particularly in light of agricultural area fragmentation and climate change challenges.