English abstract
Tomato is the major vegetable crop grown in Oman. The production is entirely dependant on imported hybrids and these are not met by any regulatory mechanism leading to exploitation of farmers. The production is restricted to mild winter months of the year while most summer remains untapped due to lack of heat tolerant cultivars. There is a need to develop indigenous breeding program for evaluation and release of exotic germplasm (hybrid and pure lines) as well as to develop local hybrids. Fifty four genotype of tomato were acquired from AVRDC, Taiwan and evaluated for their adaptation in Oman. They were categorized as fresh market tomato, cherry tomato, and high B-carotene tomato. The experiments were conducted in two locations, Sultan Qaboos University, Al-Khoud, and in the Agricultural Research Center, Barka. Field evaluation was conducted through two seasons 2004-2005, and 2005-2006. Also, to evaluate the heat tolerant accessions, two experiments were conducted in both locations during summer 2006. The experimental design was CRD with five replications. Data were collected on fruit number, fruit size, fruit shape, total yield and TSS. Biochemical compositions of the accessions were analysis (moisture percentage, ash percentage, crude protein percentage, crude fiber percentage, crude fat percentage, nitrogen free extract percentage and lycopene content). Results showed significant variation for yield, fruit number, fruit shape and TSS within varieties and locations. For fresh market CLN2545A, CLN2498E, CLN2498D, PT4664B, CLN2001A, and CL5915 showed promising results in relation to yield and fruit number over years and locations. Most of the accessions had TSS between 4 to 6.5%. In high B-carotene tomato, the high yielding and large fruited accessions were CLN2366A, CLN2071C and CLN2366B. Fruit size was varied between accessions. The TSS ratio in this category ranged from 4 to 6%. For cherry tomato, the variation in yield and fruit number was observed within varieties and locations. CHT1050C, CHT1050SB, CHT1050SG and CHT1050SA were the highest yielding accessions within this category. The TSS of cherry tomato ranged between 6 to 8.5%. For heat tolerant accessions, results indicated that these lines have a limit of heat tolerant below 44°C because accessions died when temperature exceed than this temperature. The accessions varied significantly (P<0.05) in their chemical compositions. The lycopene content was varied between the accessions. The highest lycopene value was observed for the fresh market heat tolerant accession BL1173 (90.37 mg/kg tissue). Results of the evaluation experiments showed adaptation of some accession to the local condition.
