Physiological, Morphological and Genetic Evaluation of some Guava Seedling Trees Growing in Alixandria, Qaluobyia and El Beheira Governorate, Egypt.

This work was conducted during 2020 and 2021 growing seasons on selected guava trees (8 years old) planted apart at (3 x 3 m) using traditional irrigation, a Randomized Block Design with a plantfor each genotype. These trees received the recommended management at private orchards in Alexandria, Qaluobyia and El-Beheira governorates as well as El Sabahia Research Station Laboratory.Theobjective of this work is to be to assess the best genotype from four genotypes concerning the vegetative, flowering, and fruit quality and yield. The results cleared that, genotype V3 has an overall distinct attributes other trees in vegetative growth, i.e., “plant height (m), number of  new shoots, leaf, length (cm), width and leaf area (cm²), number of flowers, fruit set %, number offruits/tree and yield (kg/tree), fruit length, width, fruit weight and pulp thickness (cm)” as well as fruit TSS (%) and vitamin C (C mg/100 ml) during two seasons. On the contrary, the genotype V1 recorded the lowest values in all vegetative growth, flowering, yield and fruit quality (physical and chemical) parameters during two seasons except (seed number and acidity %). On the other hand, the Genotype V2 scored intermediate among the highest and lowest Genotypes (V3 and V1) during the two seasons of study.
The result of this we recommended the genotype V3 to be propagated via vegetative method and distributedon acommercial scale as a superior one.
The  Genetic study using specific primer for salt Stress tolerant gene in Psidium guava indicate that genotype ElSabahiastrain  bands that  could be the band  between 700 and 800 Bpfor a marker for the salt tolerance resistant in  Psidium Guava L. So we also recommended the genotype ElSabahia strain to be propagated through Tissue Culture technique and distributed commercially as asalt stress tolerant Rootstock for Guava varieties.