ALLELE DIVERSITY FOR ACID VACUOLAR INVERTASE GENE Pain-1 FRAGMENT IN POTATO (Solanum tuberosum L.) VARIETIES AND LINES

Abstract

A b s t r a c tThe economic efficiency of potato production depends not only on the yield quantity and quality, but also on the tuber storage conditions. The tuber nutritional and technical value is determined by the starch content. Under the cold stress, the starch degrades into reducing sugars (coldsweetening), which significantly reduces the tuber quality. Plant invertases catalyze irreversible hydrolysis of sucrose into glucose and fructose. Nowadays it is definitely known that vacuolar acid invertase (Pain-1) plays a major role in the cold induced sweetening of potato tubers. In the present work genetic diversity and allelic polymorphism of Pain-1 gene associated with important agronomical traits of potato tubers is characterized. Gene fragment (exon 5-exon 7) polymorphism was analyzed in 69 cultivars and lines of Russian and foreign breeding origin. In the Pain-1 nucleotide sequences, 66 SNPs were identified, were described for the first time. The studied fragment contains a significant replacement for SNP1544 (C/A) which correlates with an increased starch content in the tubers and is homozygous in the Kazakhstani varieties Ulan and Astana. In the exons, 27 out of 42 SNPs led to amino acid substitutions. Most accessions had single amino acid substitutions. The maximum substitution number (seven to eight) characterized the Zhukovskii ranii variety and the lines 165 and 162. No substitutions were observed in the Frittella variety and the line 84. Therefore, the common level of gene fragment polymorphism in the analyzed potato accessions was shown to be rather high. Among the analyzed sequences, 78 allelic variants were described, including 64 specific variants and 14 variants common for several accessions. The obtained data may be helpful in potato breeding for an increase in starch content.

Allele Variability of Amylase Inhibitor Gene Ai in Potato Varieties and Lines

“…В кодирующих последовательностях было обнаружено 134 вариабельных сайта, а степень полиморфизма составила 21,3 %, что значительно выше, чем у других известных генов углеводного обмена. Так, исследования специально выбранного полиморфного фрагмента гена кислой вакуолярной инвертазы Pain-1 (экзон V-стоп-кодон) у сортов S. tuberosum показали, что вариабельность этого участка не превышает 9 % (37,38). У 192 линий картофеля из Новой Зеландии при анализе генов, ассоциированных с фосфорилированием крахмала, наиболее полиморфным оказался ген -гликан-Н 2 О-дикиназы (GWD), вариабельность которого составила < 5 %, полиморфизм же изоформ гена крахмал-синтазы (SS I-III) не превышал 3,4 % (39).…”