Gagandeep KaurKuldeep2024-03-042024-03-042024Kuldeep (2024). Genetic variability studies in guava (Psidium guajava L.) genotypes for growth, yield and quality attributes (Unpublished M.Sc. thesis). Punjab Agricultural University, Ludhiana, Punjab, India.https://krishikosh.egranth.ac.in/handle/1/5810207346The present study was carried out at Fruit research farm, PAU Ludhiana from 2022 to 2023 to assess phenotypic variability among twenty seven guava accessions for tree growth, fruit yield and quality. The varieties Punjab Pink, Pear shaped and Allahabad Safeda, had spreading growth habit, while the other varieties under evaluation had intermediate growth habit. The varieties like Punjab Kiran, Pant Prabhat and Punjab Pink were vigorous, while the others were semi-vigorous. The leaf length was maximum i.e. 146.05 mm in CISH G-5. The varieties Allahabad Safeda, Pant Parbhat, Hiasar Safeda, Punjab Kiran, CISH G-5, CISH G-35 and Taiwan Pink had oblong leaf, while Pear Shaped had obovate leaf shape. The other varieties had lanceolate, oblanceolate and round leaf shape. Acute apex was noticed in variety Punjab Pink, Shweta, HB-88, MPAUTN S-1, and CISH G-1. Likewise, the leaf base in different guava varieties ranged from acute-obtuse. The maximum fruit size (length 91.67 mm; breadth 92.45 mm) was recorded in variety Allahabad Safeda. Fruit shape was round in most of the varieties, while Punjab Pink had ovate fruits and fruits were pyriform in the variety Pear Shaped. The maximum T.S.S (11.89 %) was obtained in variety CISH G-1 followed by 11.87 per cent in Seedless. The acidity in different varieties ranged from 0.23 per cent in Thailand to 0.79 per cent in hybrid Seedless. Maximum glucose content was observed in case of CISGH-5 cultivar. Sucrose content varied from 1.86 to 9.85 per cent. Fructose content varied from 2.04 to 7.77 per cent among the varieties. The total number of seeds per fruit ranged from 109 in variety Seedless to 525 in Arka Kiran. The 100 seed weight, among varieties evaluated was minimum in variety Allahabad Safeda (0.88 g) and highest (3.11 g) in SRDH-4. In second experiment, changes in physico-chemical composition during fruit development and ripening in were studied in three guava cultivars namely Punjab Kiran, Shweta and Punjab Apple guava during rainy and winter season. Fruits were analyzed for fruit size, fruit weight, total soluble solids, titratable acidity, reducing sugars, Vitamin C content and bio active compounds content at different fruit development stages. Fruit length was reported in an array of Punjab Kiran> Shweta > Punjab Apple Guava during rainy and winter season. And on the other hand, fruit diameter has a different array i.e., Shweta> Punjab Apple Guava> Punjab Kiran. Fruit weight was reported in an array of Shweta > Punjab Kiran> Punjab Apple Guava during rainy and winter season. The TSS was highest (12.6%) in Punjab Kiran during winter season. Acidity was highest in Punjab Apple Guava. Total sugars were highest in case of Punjab Kiran (7.91%) during winter season while reducing sugars were the highest in Shweta. Vitamin C content was highest in Punjab Apple Guava (193.6 mg/ 100 g pulp) among three varieties. Bioactive compounds like anthocyanin and carotenoids were maximum in Punjab Kiran during ripening stage. While phenol content and total flavonoid were maximum in Punjab Apple Guava among the three varieties during winter season. Pectin content varied in all the three varieties and was maximum (1.12%) in Punjab Apple Guava at 90 DAFS during rainy season. Antioxidant content was highest in Punjab Apple Guava.EnglishThesis