Contribution of root anatomical characteristics in fruit profile of pomegranate genotypes to expand production area in Pakistan

Abstract

Pomegranate adaptation to abiotic stress conditions has led to its wide dispersion in Pakistan and to the appearance of new, local genotypes. These genotypes are important to characterize for breeding programs aimed towards the production of new cultivars suitable to arid, semi-arid, and moderate weather regions. In this study, eleven pomegranate accessions were investigated for fruit morphological and biochemical traits, and root anatomic adaptation under diverse climates. The commercial accession (Sava) had the maximum fruit weight (373.97 g) compared to accessions KK-I (60.94 g) and KK-II (71.63 g), which were old plantations established since United India. Most of the accessions were juicy with a wood portion index (WPI) ranging from 0.93 to 1.06%; however, the non-commercial accession of Khushab Kanhatti (KK-I) showed the highest WPI (4.38%). A high variation occurred among all accessions for total soluble solids, total sugars, and total ascorbic acid contents with a maximum in accession Sava (16.46°Brix), TK-II (53.16%), and QW-I (0.68%), respectively. Root anatomical studies in accessions depicted significantly high variation, and accession Sava of semi-arid climate produced maximum root epidermis (97.43 μm2), phloem (2730.78 μm2), and metaxylem (717.77 μm2) area. In contrast, high cortex thickness (104.74 μm), cortex area (462.74 μm2), and vascular area (114,382.10 μm2) was measured in accessions KK-II and KK-III of Khushab district with an arid climate. The germplasm of diverse regions showed a strong association and clustered into two main classes based on fruit morpho-chemical and root anatomical characteristics. These traits are likely to provide clues towards plants adaptation to various growing conditions and can be exploited successfully in crop improvement programs.