Agronomic traits and phytochemical content of popularly grown tomato cultivars in Malaysia / Khor Jing Herng

• Main Author: Khor , Jing Herng
• Format: Thesis
• Published: 2022
• Subjects: Q Science (General); SB Plant culture
• Online Access: http://studentsrepo.um.edu.my/14751/1/Khor_Jing_Herng.pdf; http://studentsrepo.um.edu.my/14751/2/Khor_Jing_Herng.pdf; http://studentsrepo.um.edu.my/14751/

Tomato is a popular crop because of its taste and nutritious value. Despite many tomato cultivars being found in the market in Malaysia, several of them are only known by their trade name and nothing much is known about the agronomic traits and phytochemical profiles. Systematic profiling of flowering, fruit yield and phytochemical content for tomato cultivars can aid in establishing a platform to support cultivar improvement studies. To study tomato cultivars in Malaysia, a survey was conducted among seed producers and online-shopping platforms. It was found that at least 38 tomato cultivars are grown in Malaysia and that these have variable agronomic traits. Empirical knowledge was gained on tomato farming, from seed sowing to fruit sorting, via interviewing four farmers during an educational farm visit at Cameron Highlands. Among the 38 cultivars, the three most popular cultivars Red Rock, Super Star, and Tropical were selected for collection of detailed agronomic trait information and phytochemical characterisation in controlled growth conditions. Among the three cultivars, Super Star showed the highest germination rate (100.00 ± 0.00 %). Red Rock showed the highest plant height (277.90 ± 1.4 cm), leaf number (288 ± 2), flowering rate (68 ± 1 flower plant), fruiting rate (60 ± 1 fruit/plant) and the shortest flowering (125 DAP) and fruiting time (136 DAP). Flowers of all cultivars showed differences in petal and sepal numbers and reproductive phenology such as pistil, pollen and ovary. In fruit morphology and characteristic analysis, it was observed that fruit of Tropical showed the highest fruit area (40.31 ± 2.25 cm2), fresh weight (64.90 ± 2.13 g) and dry weight (4.63 ± 0.34 g). Among all cultivars, fruits of Super Star showed the highest phytochemical content, DPPH inhibition (89.69 ± 1.46 %), total phenol content (164.57 ± 1.91 mg CE/100 g DW), total anthocyanin (4.81 ± 0.32 mg ME/100 g DW), total flavonoids (163.29 ± 3.41mg CE/100g DW) lycopene (2.18 ± 0.02 mg/100g FW) among three tomato cultivars. Fruits of Red Rock showed the highest total sugar content (1503.74 ± 0.93 mg/100g FW). Vitamin C (ascorbic acid) content (74.68 ± 1.74 mg/100g FW) was highest in fruits of Tropical cultivar. Principal component analysis (PCA) showed a strong correlation between fruit characteristics and phytochemical properties, depicting that with the exception of fruit area, these parameters can be used to differentiate tomato cultivars. Red Rock was characterized by relatively high values for moisture content, total flavonoids, and total sugar; Super Star was characterized by relatively high values for TPC, total anthocyanin, fruit area, DPPH inhibition and lycopene; Tropical was characterized by relatively high fresh weight, dry weight and ascorbic acid content. It was also found that lycopene, TPC, DPPH and total anthocyanins were positively correlated with each other and negatively correlated with ascorbic acid content. On the other hand, total flavonoids and total sugar were positively correlated with each other and negatively correlated with lycopene and fruit weight. This data from this study could be used as a reference in selection of desired tomato cultivars.