In Iran, as in other developing countries, SEED tuber is a major constraint to POTATO production. Thus, it is logical to consider the use of TRUE POTATO SEED ((TPS)) in Iran, as in some countries such as China. This study involved two experiments. In Experiment I, (TPS)-derived tubers from 12 progenies were compared to those of four cultivars. The cultivars were superior, regarding yield, number of tubers and tuber weight. However, compared to progenies, they had less uniform tubers, mainly due to more within-plant variation. Experiment II involved 5 progenies, 2 methods of elimination (eliminating small tubers or poor plants) and 2 intensities of elimination (eliminating the first 10% or 20% of small tubers, or poor plants). Eliminating the first 20% of small tubers resulted in significant 7% increase in yield per plant and improved tuber uniformity by 2%.

In order to obtain advanced clones of POTATO crop and to utilize them as SEED source or developing new cultivars, an investigation was conducted in 2004 using 120 new clines obtained from TRUE POTATO SEED and Agria, Marfona, Draga, Agata and Arinda as control cultivars in an augmented design based on randomized complete blocks with three replications in Ardabil area. Yield of each clone was adjusted for block effects, and then compared with each other using LSD method. The clone numbers 21 and 110 had the lowest and the highest yields, respectively. The clones 110, 19, 46, 41, 91, 44, 78, 111, 70, and 101 had high tuber yield over 31 ton/ha, and the difference between them and high yielding control cultivars was significant. With respect to dry mater yiled per unit area, the clones 41, 110, 19, 44, 91, 46, 74, 42, 84, and 81 had the highest yield with dry matter content of 1.0659, 0.9406, 0.9119, 0.8980, 0.8903, 0.8852, 0.8522, 0.8352, 0.8320 and 0.8299 kg m-2, respectively and were selected as promising clones.

In this study the effects of irrigation method, variety, and planting date on the production of TRUE POTATO SEED ((TPS)) were investigated in Golgeh Rokh Agricultural Station in Khorasan Province. Statistical design was a strip split plot with three replications. The irrigation methods (Drip, Farrow and Sprinkler irrigation), arranged in vertical blocks, varieties (Picaso, Famoza and Granola) in horizontal blocks and planting dates (May 26, June 10 and June 25) as complete blocks in subplots. The study, Furrow irrigation had the highest amount of (TPS) but it was not significantly- different from the trickle irrigation. Water consumption was also lower in trickle irrigation. Among the varieties, Picaso had the highest and Granola the second highest yield of (TPS). The second planting date showed the highest (TPS) production than other planting dates (25 Jun. and 26 May). In conclusion picaso produced highest (TPS) (27.72 kg/ha) under furrow irrigation and planting date of June 20.  

In order to evaluate the possibility of the use of hybrid mini tubers in POTATO production, nine (TPS) families including Desiree×Payezeh, Caesar×Payezeh, Caesar×Aula, Aula×Desiree and Draga ×esiree Hybrids and Desiree, Aula and Daiezer open pollinated populations with five Clonally varieties: including Aula, Caesar, Desiree, Draga, Astrix were compared in an augomented design based on completely randomized blocks. Agronomic traits such as plant yield, plant height, number of stem in plant and number of tubers in plant were noted. The results showed that there are significant differences among treatments for plant height, number of stems and number of tubers and yield. Desiree variety with 557gr per plant yield and then Desiree×Payezeh and Caesar×Payezeh hybrids with 549 and 445gr per plant yield respectively had the higher yield. The least yield was of Aula×Desiree and Payezeh×Aula hybrids. The Desiree×Payezeh hybrid had the highest and the Draga variety and open pollinated Caesar had the lowest height respectively. Astrix and Desiree varieties with average stem number of 4.5 and 4.4 had the highest number of stems. Concerning the number of tubers, Desiree×Payezeh Hybrid with average 20 tubers and Draga with average 4.6 tubers had the highest and lowest number of tubers respectively. The study of correlation coefficient between traits showed a significant relationship between yield plant with the numbers of stem and height of the plant, and also the plant height showed a significant relationship at 5% probability level with the number of tubers and stems.

To create genetic variations in POTATO during four years of study (2007-11) and use than in breeding programs, some 105 hybrids were selected from cresses of Agria, Savalan, Boren, Kennebek and Ceaser cultivars as hybrids parents, and planted in augmented design at the Agricultural and Natural Resources Research Station of Ardabil during 2010-2011. The marketable tuber yields produced by the parents and hybrids were 42-52 t.ha-1 and 10.4-138.8 t.ha-1, respectively. The marketable tuber yields of hybrids exhibited 23.81% over dominance, 52.38% incomplete dominance, 13.33% reduction dominance and 10.48% interval dominance. Almost 24% of all hybrids selected produced higher marketable tuber yield than their parents. Heterosis for marketable tuber yield was found to be 58%. Based on the traits considered like marketable tuber yield, tuber uniformity, shallow eye depth, short stolon and yellow flesh and skin color, heterosis and dominance degrees some 28 hybrids were selected. Among hybrids selected, 14 belonged to ♂ Ceaser × ♀Savalan cross (021, 022, 023, 025, 026, 049, 057, 081, 087, 088, 095, 098, 0104 and 0105), four to ♂ Savalan × ♀ Agria cross (0500, 0502, 0503 0508), five to ♂ Ceaser × ♀ Agria cross (0611, 0613, 0616, 0618 and 0623) with early to mid-early maturity group, one to ♂ Boren × ♀ Savalan cross (0205), two to ♂ Savalan × ♀Ceaser cross (0300 and 0303) and two to ♂ Ceaser × ♀ Kennebek cross (0401 and 0403) with mid-late maturity group.

Introduction: The using of TRUE POTATO SEED ((TPS)) could be overcomes some of limitation in POTATO production in developing countries. The development and acceptance of (TPS) cultivars depend on the production of suitable (TPS) cultivars with high homogeneity and yield. The hybrids between the selected Andigena clones with Tuberosum are one of the approaches to developing such cultivars. Material and methods: Some clones of S. tuberosum ssp. Andigena that has been selected previously from the three cycle of population breeding for adaptation to long condition in university of Tabriz, were used in cross with four tuberosum cultivars (Diamond, Moren, Picasso and Satina). Totally 12 (TPS) families including the four Tuberosum× Andigena hybrid family, five Tuberosum× Tuberosum hybrid, one Tuberosum OP along with two Andigena population (selected and non-selected) were compared with experimental layout as complete randomized block design with three replication. The evaluated traits were number of tuber, yield per plant, tuber appearance and tuber dry matter. Result and discussion: Analysis of variance showed significant difference between the families. The highest and lowest tuber yield was belonging to Picasso× Satina and unselected Andigena respectively. The highest tuber number was observed in Picasso Andigena and selected Andigena family and Picasso Op had the lowest tuber number. Results indicate the superiority of some Tuberosum× Andigena for yield and dry matter in relation to Tuberosum× Tuberosum. But for tuber appearance generally Tuberosum× Tuberosum were better than the Tuberosum× Andigena. The yield and dry matter of selected Andigena population was better than Picasso OP progeny and non-selected population of Andigena. The orthogonal comparison between the families having the Andigena germplasm versus pure Tuberosum showed that except the dry matter in the other evaluated trait there was significant difference between two groups, and the mean yield and tuber number in families having the andigena germplasm were higher than pure tuberosum. These results indicate the importance hetrosis in yield and other traits of POTATO. Conclusion: Three cycle of selection on original Andigena improved its yiel and tuberization in long day condition yet its tuber appearance did not changed. Hybrids of tuberosum andigena had yield similar to tuberosum material. Considering that andigena had the same ploidy level with cultivated POTATO and its rapid response to selection under long day made it suitable choice for broaden the genetic base of cultivated POTATO.

This study investigated the mechanisms of SEED POTATO managementby POTATO growers of Freydunshahr County in Isfahanprovince. Survey research method was used in thisstudy. A sample of 250 POTATO growers (N=725) was selectedfor data collection. Stratified random sampling method wasused. The research instrument was a questionnaire that wasvalidated for face validity by a panel of faculty members andagricultural experts of Agriculture Jihad Organization in FreydunshahrCounty. For determining the reliability, Cronbach'salpha was estimated which turned to be higher than 0. 7. Resultsshowed that "a part of tubers produced by farmers" was thefirst priority of farmers as SEED tuber source. Results showedthat 89. 6 percent of POTATO growers store and keep SEED tubersin inappropriate conditions. Majority of the farmers did nothave sufficient information on SEED POTATO management andthere was a positive and significant relationship between thefarmers’ education and POTATO yield per hectare, but a negativerelationship was found for age. Based on logistic regressionanalysis, the predictive power of the model was 0. 639 and thesensitivity of total model to determine the correct percentagewas 86. 0 percent. Among individual, professional and economicfactors, variables of age, number of family labor, area ofowned land, area of POTATO farming, POTATO yield per hectare, number of owned land parcels and knowledge and informationlevel of respondents significantly impacted on the adoptionand use of modern SEED POTATO production systems.

Introduction: POTATO (Solanum tuberosum L. ) is widely grown in different environments, forming the fourth largest crop in the world, with a production of almost 321 million metric tons. SEED POTATO degeneration, the reduction in yield or quality caused by an accumulation of pathogens and pests in planting material due to successive cycles of vegetative propagation, has been a long-standing production challenge for POTATO growers around the world. In developed countries this problem has been overcome by general access to and frequent use of the SEED, produced by specialized growers, that has been certified to have pathogen and pest incidence below established thresholds, often referred to as certified SEED. POTATO leaf roll virus (PLRV) and POTATO virus Y (PVY) are the most important viruses infecting POTATO crops and also reduce the size as well as a number of POTATO tubers with annual global yield losses of up to 20 million tonnes. In Iran, PLRV and PVY are widely distributed in most POTATO-growing areas in Iran and have caused severe yield losses of up to 40 percent. This study was carried out to evaluate the amount of POTATO SEED field’, s infection to POTATO leaf roll virus and POTATO virus Y in different regions of Hamedan province and to survey the sensitivity of cultivars to studied viruses. Materials and Methods: Leaf samples were prepared from POTATO SEED field (S SEED class) which has a 3-years rotation and 400 meters isolated distance from other POTATO growing fields. Studied POTATO SEED fields were located in three regions of Hamedan province included: KaboodarAhang, Goltappe and Razan. These regions are the main POTATO production areas in Hamedan province of Iran. Leaf samples infection to POTATO leafroll virus and POTATO virus Y was determined by DAS-ELISA test using specific antiserum (Patho Screen Kit, supplied by Agdia Incorporated, USA) following the fundamental protocol outlined by Clark and Adams (1977) ELISA assay. The yield of all studied fields was determined after harvesting. Meteorological information of three SEED production areas included average temperature, rainfall and wind speed was collected during the studied period. Results and Discussion: Results showed that infected POTATO plants by both studied viruses (POTATO leaf roll virus and POTATO virus Y) were seen in KaboodarAhang region, while POTATO plants infected by studied viruses were not seen in the other regions (Goltappe and Razan). The probable cause of higher virus infection in KaboodarAhang region could be due to the wider migration of carriers and their greater activity in the region which had higher average temperature and rainfall than the other two studied areas. In Goltappe region which was diseases free, the temperature means and the amount of rainfall was lower than the other regions during the growth period. Maximum wind speed (25 m. s-1) in the infected region (KaboodarAhang) was higher than regions which were free of diseases (Goltappe and Razan). The wind blowing provides the possibility of transmission of viral infection by aphids (especially Myzus persicae) from neighbor infected fields. However, portable flight capacity such as the aphid Myzus persicae may rarely exceed 100 meters, but Wind-assisted flight can carry aphids for several hundred kilometers. Therefore, what matters more than the isolated distance between POTATO SEED production fields is the health of the SEED production area and the speed and direction of the wind. Among studied cultivars, Agria and Arinda cvs. were infected by both studied viruses, while the other studied cultivars (Sante, Banba and jelly) were not infected. In Agria cv. and in the range of infection between 1 and 3%, the relationship between yield and POTATO plants infection to PLRV and PVY was not found, but in Arinda cv., the yield of virus (PLRV and PVY) free fields were much higher than those of infected by PLRV and PVY. Conclusion: Since the Agria and Arinda cvs. were infected by POTATO leaf roll virus and POTATO virus Y, this can be concluded that these cultivars are sensitive to POTATO leafroll virus and POTATO virus Y. It seems Goltappe and Razan regions are suitable for POTATO SEED production in Hamedan province. In the low range of viral infection, no logical relation was seen between POTATO plant’, s yield and viral infection of plants. Among studied meteorological parameters, temperature mean and the amount of rainfall in the free of diseases region are lower than infected region.