Mutation of the VAR2 gene plays a role as one of the causes of leaf variegation in the Moth Orchid Phalaenopsis 'Sogo Vivien'
Penulis/Author
FEBRI YUDA KURNIAWAN (1); SAIFA USNI PUTRI (2); AVIESTA LINGGABUWANA (3); MUHAMMAD DYLAN L (4); Prof. Dr. Ir. Aziz Purwantoro, M.Sc. (5); Prof. Dr. Endang Semiarti, M.S., M.Sc. (6)
Tanggal/Date
23 2024
Kata Kunci/Keyword
Abstrak/Abstract
Phalaenopsis 'Sogo Vivien' is a hybrid orchid that can produce a mutant with a foliar variegation.
Variegation can be divided into structural type and pigment type variegation. Foliar variegation was
mostly caused by mutation on plastid genes. Even though there are various studies for foliar variegation
on other plants, studies on foliar variegation in orchids are quite limited. This study aimed to determine
the leaf of variegated phenotype characteristics and its cause in P. 'Sogo Vivien'. This study observed the
anatomy of variegated leaves by comparing the green and white part of the leaf, measured the
concentration of chlorophyll pigments and detecting leaf starch content between both parts. In addition,
polymorphism analysis was also performed on the VAR2 gene partial sequences. Based on leaf anatomy
structure, the difference between variegated sites is only in the number of chloroplasts, diameter of
parenchyma cells and chloroplasts. Chloroplast diameter within the white part is smaller than green part.
Chloroplasts diameter in the green part are two times larger than the white part with four times more in
amount. The two parts were formed due to differences in the distribution pattern of functional
chloroplasts in the leaves. The concentration of chlorophyll in the green part is higher than the white part,
a characteristic of the chlorophyll type variegation. The green parts have more starch grains than the
white part. Stomata distance between variegated zones in the abaxial side is different and it was suggested
as distinctive character between variegated zones. A thymine insertion in the exon 1 contributed to
nonsense and missense mutation on VAR2 gene isolated from the white part. This mutation caused amino
acid motif changed from KAKFQ to KA—Q. This mutation is suggested to cause the variegated leaf
phenomenon in P. 'Sogo Vivien'.
