Evaluation and identifying potato cultivars grown in high altitude or latitude for high growth vigour

Increasing potato yield by using certified seed for farmers has been known for many years. Since, super elite and elite seed potato production is very sensitive process in the potato production cycle, therefore insufficient production of basic seed will be resulted in more dependency to importing of potato seed tuber from foreign countries. So, each method that can increase the number of seed generation with a healthy tuber will be resulted in decreasing of seed potato imports and also will help to ensure food security. Being a superior product using produced seeds in highlands is attributed to potato seed free from viruses and some physiological traits of seed tubers. This research was conducted at two locations in two consecutive years. At the first year a farm in the highlands of ChaharMahal and Bakhtiari and also a farm in the low altitude in Alborz province were selected and planted. Ten potato cultivars were planted in 4 replications based on randomized complete block design, at the first year. The harvesting of seeds from different maturity groups as early, middle and late maturity under two different climatically conditions at provinces was done at the first year. The produced seed potato at the first year under different climatically conditions in low altitude areas in Isfahan with four replications based on split plot design was evaluated at the second year. Results of simple analysis of data in the first year in both places showed significant difference among cultivars with exception of shoot dry weight in two regions; shoot fresh weight, harvest index in Karaj and also the average specific gravity of tubers in the highlands region. According to results of combined analysis in the first year, the significant differences were observed among majority of traits in two regions and different cultivars. So that, traits as number of days to full flowering, total weight of tubers per plot, shoot dry weight, the average number of tubers produced per plant and also total yield of tubers were different and higher yield was related to the highlands region. The meaningful difference among cultivars for all traits except dry and fresh weight of shoot was observed. Health assessment of seed potato produced in both regions confirmed PVY infection in different cultivars in the first year. Statistical analysis of the second year data showed significant differences except of shoot fresh weight, days to full flowering, number of stem per plant and average number of tubers per plant in seeds produced from both locations at the first year in low altitude area in most traits. Seeds from highland areas were noticeably superior than seed produced in low altitude region. The meaningful differences were observed among cultivars from the aspect of all traits except of percentage of emergence, shoot dry weight and harvest index. Health assessment of plants with two seed originating at the second year showed more PVY infection than first year. The more PVY infection was related to seeds that originated from lower elevation. It is noteworthy that there was no PLRV infection during two years