Establishment of apical shoot meristem culture for in vitro conservation of sunflower (Helianthus annuus L.) genetic resources

Abstract

A high regeneration capacity is important for in vitro conservation of genetic resources and transformation studies. The research was conducted at Uludaǧ University, Agricultural Faculty, Field Crops Department, and Plant Tissue Culture Laboratory in 2011. Ten genotypes (T0910817-1, T0910950-2, T0910791-3, T0910182-2, T0910792-1, T0912285-1, T0911033-2, T091-0791-1, T0910791-4 and T0910930-2) were used as plant materials. The apical shoot meristems of sunflower genotypes (Helianthus annuus L.) were dissected from 4 day-old seedlings and transferred to MS medium allowing shoot and root development. The experiments were placed into growth chamber in 16/8 hour light/dark photoperiod at 26±2°C for two weeks. They were transplanted into vial containing a 1:1:2 peat-erlite-soil mixture (v/v) for acclimatization, covered with nylon bags and kept at 25±2°C in 16h/8 h (light/dark) in a growth chamber for 2 weeks. Young plantlets were transferred to unsterile soil and developed to maturity. They were self-ollinated in the natural conditions. The agronomic characters (plant height, head diameter, number of leaves, stem diameter, number of branches) of in vitro grown plants were measured before harvesting. The data was analyzed with Jump statistical programme in the completely randomized design with 3 replications, each replication consisted of one pot with 6 plants. Out of 10 genotypes, seven showed a notable response to the in vitro establishment. The 67.33% of all cultured apical shoot meristems developed into vigorous plantlets with 3-6 leaves. The majority of the developed plantlets had vigorous root. Almost all of the plantlets grew healthy and produced fertile plants in green house conditions. The analysis of variance for all agronomic characters, except for the number of branches, resulted in significant differences among genotypes at 5% level. The genotype with a relatively high regeneration capacity and agronomic performances was T0911033-2 followed by T0910950-2. Plant regeneration from apical shoot meristem of sunflower ispractical and efficient when appropriate genotype and sterilization procedure are used.