Plating Media: R medium + 2 uM metatopolin + 12, 1cm3 cubes Russet potatoes. 45 mins. bleaching with 0.525% Chlorox bleach
Replating Media: R medium + 1, 1cm3 cube russet potato
Number of Days between Plating and Replating: 125 days
Number of Days between Replating and Vernalization: 210 days
Number of Days between start and end of Vernalization: 120 days (4 months)
Date to Initiate Plating: Dec. 31
Date to Replate: May 4
Date to start to Vernalize: Dec. 1
Seedlings were plated on 10-27-09, replated on 03-01-2010, and started vernalization on 09-27-2010. Seedlings had 1/2 to 3/4 inch shoots and 3-4 roots 2-3 inches long. The main problem with pubescens is that the roots grow very kinky and intertwine with other seedlings. Some jars produced no seedlings, they just died. I believe that it is important to replate them very dense because it appears that the seedlings interact with one another and promote growth. The problem with this is that the seedlings get badly intertwined. I guess one just has to live with this. So, replate protocorms densely perhaps at 40 protocorms per jar. Also, because growth appears slow, suggest trying 2ip (2 uM) as an alternate to 2 uM metatopolin. Try experimentation with next year's seeds. Vernalization needs to start by Dec. 1 to keep process synchronized and not too long.
This year tried two different replate media, one with R medium + 1, 1cm3 cube Russet Potato and R medium + 1, 1cm3 cube Russet potatoa + 20 ml/l pineapple juice. Both replate media produced good roots and shoots up to 1/2 inches long. Could not detect any difference in the media supplemented with pineapple juice.