A Simplified Technique for the Propagation of Shoots from Nodes of Switchgrass (Panicum virgatum L.) Genotypes

Abstract

Nodal propagation of switchgrass (Panicum virgatum L.) is an important technique for multiplying a variant plant, with a potentially valuable agronomic trait, for replicated field trials. To develop an improved propagation system, shoot induction from three node positions (low, mid, and high) was tested in ten genotypes of switchgrass cv. Alamo. Nodal segments were incubated in a custom hydroponics system with 1/4 strength Murashige and Skoog liquid medium for 6 weeks. In all genotypes, shoot formation was highest at the low node position, the largest nodes, ranging from 60 to 98 %. From the ten genotypes tested, three genotypes (4, 5, and 6) had a significantly higher shoot formation at mid and high nodes with a shoot formation greater than 80 and 50 %, respectively. Shoot formation for all other genotypes at the same two positions was less than 40 and 10 %, respectively. In a single replication, 30 shoots from the lowest node position of each genotype were rooted for 4 weeks in each of two rooting conditions (RC1, Rootone dip and soilless media and RC2, IBA in a half-strength liquid MS media). Four genotypes showed greater root formation in RC1, while one genotype showed greater root formation in RC2. In this paper, we describe a procedure for generating a population of genetically identical plants from switchgrass, in as little as 6 weeks, that is relatively inexpensive, efficient, and does not require specialized equipment needed for tissue culture.