Dissertation for Master's Degree in Agricultural Engineering
Plant Pathology Orientation
Abstract
The nematode Globodera rostochiensis had not been reported from Iran before 1387. The high contamination of the nematode in the potato fields of Hamedan province is a serious threat to production Potato, which is the economic product of this region.
Considering the seriousness of Globodera rostochiensis damage to Iran, so far not much information has been collected about determining the economic damage threshold of the nematode in cultivars cultivated in Hamadan province. Therefore, this research was investigated for the first time in Iran on two potato varieties, Marfona and Sante. Contaminated soil samples were collected from Hamedan province and after phenocrysts cysts were isolated to prepare the nematode population. This research was carried out in seven treatments with three repetitions. The first control treatment and then the treatments included 2, 4, 6, 8, 16, 32 and 64 seeds per gram of soil.
After cultivating the two cultivars in four kilo pots containing sterile soil after rooting, the populations prepared around the roots were inoculated and harvested after three months of the treatments. and the results were analyzed.
According to the statistical investigations on growth factors and nematodes that were carried out with Mstatc software, it was concluded that Sante variety is resistant to Globodera rostochiensis, and in the case of Marfona variety, according to the hatching rate of nematode factors, the economic loss level of four eggs per gram of soil was obtained.
Key words: Globodera rostochiensis, golden cyst nematode, resistant potato varieties, Marfona variety, Sante variety, level of economic loss of golden nematode
1 History of potato
Potato from the Solanaceae family is one of the best agricultural products that is very important as a valuable food and industrial material in most parts of the world.
According to archeological studies, from seven to eight thousand years ago, farmers in Peru have cultivated wild types of potatoes. Based on this, the researchers have declared the origin of this plant in the Andes region of Peru. According to the researchers, the Inca Indians discovered it for the first time in 2000 BC, and in 1537, the Spanish soldiers became aware of its cultivation by the Inca Indians, who called it Paya. This product then entered Spain and from there to Italy and other countries. It spread to Central Europe and gradually became a staple food product in Europe, especially in Germany, Russia and Ireland (Hasanpanah; Nikshad and Hosni, 1378).
Some others believe that potatoes were first sent from Ireland to England. An English lord named
"Servalter Raleigh" cultivated it in his farm near "Kirk" and later it went to Germany, Austria and Russia (Omidwar, 1348).
In the early 17th century, potatoes were offered in the palaces of the kings and then in the palaces of European nobles as an expensive food item. The 19th planting of potatoes was used as a raw material for consumption in alcohol and starch factories. Anyway, its main origin is in South America, where it still grows wild in some places, and its wild varieties that show resistance to the disease are used to obtain new domestic varieties.
In recent years, potatoes were imported to many countries with hot and dry climates and in areas such as North Africa, the plains of India, Bangladesh, Pakistan, Central Africa, China, Argentina, Uruguay and The plains of the coast of Peru have been developed.
1-2 Botanical characteristics of potato
Potato with the scientific name Solanum tubersoum botanically belongs to the Solanaceae family, in which there are other important plants such as tomatoes, eggplants, and peppers. The species of this genus are abundant in tropical regions and their abundance gradually decreases towards temperate and cold regions (Kaherman, 1373). According to the studies conducted, different potato species are distributed from Chile to the south of the United States and from sea level to an altitude of 4800 meters.
The origin and the main area of ??distribution of this genus is the western regions of South America, i.e. the countries of Peru, Chile, Bolivia, Ecuador, where about 40 species of this family grow there. Ten species of it are distributed in Europe, 15 species in Asia, and finally 10 species in Africa, and among these, 12 species of this genus are also scattered in different regions of Iran. and food should be considered as one of the important genera of plants (Falahi, 1376).
In potato, the number of chromosomes in the genus Solanum is twelve. The mini apple is a herbaceous and perennial plant, but it is cultivated as an annual plant in agriculture. This plant usually reproduces through the seed tuber. From the buds on the seed tuber, branches and organs Aerial roots are created. Roots are formed from primordia on buds. On these branches and aerial organs, stems and leaves, stolons, roots and inflorescences, as well as the next generation of tubers, are formed. style="direction: rtl;">General morphology:
The morphology of the upper and lower parts of the soil surface in potatoes depends on the physiological age of the cultivated seed tubers, and in this way, the growth pattern of each single stem according to its initial strength, the number of leaves formed on each stem, the time of stolon formation, the time of growth and branching of stolons, the beginning of tuber formation and flowering, the duration of formation and growth tubers, the beginning of senescence and the length of growth and growth period of the plant are affected.
Stem system:
Since each eye on the potato seed tuber can produce more than one stem. And considering that on each seed tuber, many buds have the ability to produce stems, it is natural that a number of stems are formed from each tuber. Therefore, in the field, a set of stems branch out from a potato seed tuber in the form of a cluster. In the early stages of growth, these stems provide their food resources from the seed tuber, but in a short distance after the sprouting of each stem, they reach the stage of self-sufficiency and independence, and at the same time, they compete with other adjacent stems for light, water, and food. Usually two types of stems. One with definite growth and the other with indeterminate growth are observed in potato cultivars. In cultivars with definite growth, the height of the stems is short and each stem has a short life span. The yield potential in indeterminate cultivars is usually higher than that of cultivars with definite growth, but to realize it, the length of the growing season must be long so that the plant can reach its yield potential. The stems in the underground part of the plant are usually round and plump, but in the aerial parts of the plant in the middle of the node, they may be hollow. In addition, in the aerial parts of the plant, the stems are angular and angular. and can be seen in red to purple colors.
Leaves:
The potato plant has one compound leaf in each node of the stem. The initial leaves that appear at the beginning of potato growth are small in size, but the subsequent leaves are compound with 3-4 oval leaflets each. Potatoes have long days. And high temperatures increase the number of leaves in the secondary stems compared to the main stem.