استفاده از ژن HsBvm-1 در توسعه ارقام چغندرقند مقاوم به نماتد سیستی در ایران

Sugar beet cyst nematode (BCN) is one of the most important pests of spring sugar beet cultivation in Iran. This nematode is prevalent in most sugar beet-growing regions of the country. One of the best and most effective methods of reducing damage caused by this nematode is the use of resistant varieties. To develop a resistant variety, populations carrying the HsBvm-1 gene were first evaluated in greenhouse conditions and resistant plants were identified. Then, based on the identified resistant and susceptible plants, a molecular marker (STS) was designed and validated for the gene. Finally, with the help of this marker, resistant homozygous single plants were identified and used in the process of developing a resistant hybrid variety. In the first experiment, from five populations evaluated, four populations (SB26, SB28, SB29 and SB30) with less than ten cysts per plant were identified as resistant populations. Population SB34, with an average number of cysts of over 25 per plant similar to susceptible checks Jelgheh and Brigitte varieties, was identified as a susceptible population. In the second experiment, from five populations SB27, SB31, SB32, SB33 and SB35, only population SB27 was identified as a resistant population. In order to detect the HsBvm-1 gene based on the identified Single Nucleotide Polymorphisms (SNP), a Sequence-Tagged Site (STS) marker was designed. The designed STS marker, showed 75% correlation with phenotypic results and 88% correlation with the SNP marker. Population SB26 was used as the pollinator in the development of a hybrid variety named Aria which introduced as the first BCN-tolerant variety. Aria cultivar had 91% sugar yield in comparison with foreign cultivars in different regions of Iran under natural infected conditions. Population SB27 was also used as pollinator and the Shokufa hybrid variety was introduced as the second tolerant variety. Resistant single plants were identified from population mentioned populations using the marker. Four single plants from population SB26, one plant from population SB27, two plants from population SB29, and one homozygous plant from population SB30 with suitable quantitative (root yield) and qualitative (sugar content) characteristics were identified and used as pollinator in the development of hybrid varieties. These hybrids were selected as new BCN- resistant cultivars with the names Arta, Kimia, Nika, Tara, Hasna, Rubina, Yalda and Zeba received a commercialization license from Iran's National Plant Varieties Committee. Until now, 120,000 units (one unit of sugar beet seed is equivalent to 100,000 seeds) from these resistant varieties have been distributed to farmers with an average price of 10 million Rials per unit.