Selection for combining premature-flowering resistance with high fibre yield in tossa jute

Abstract

The present study was carried out in tossa jute (Corchorus olitorius L.) to select cross combinations between parents with high general combining ability for fibre yield and to carry forward the segregating generations for selecting transgressive segregates that can be used as high yielding varieties capable of being sown earlier than the existing varieties without risk of premature-flowering rendering them to be better fitted in multiple cropping sequence. Eleven good performing genotypes of which seven directly selected shortlisted exotic lines, collected recently from Kenya and Tanzania by International Jute Organization, viz., KEN/DS/030C, KEN/DS/038C, KEN/DS/068C, TAN/SM/046C, TAN/SM/074C, KEN/SM/024C and KEN/BU071 C showing high degree of premature-flowering resistance with good agromorphological features mainly plant height, basal diameter and optimum growth habit and four well adapted indigenous varieties viz., JRO 7461, JRO 524, JRO 7835 and JRO 36E having high fibre yield and moderately resistant to premature-flowering were intermated in non-reciprocal diallel cross fashion in 1993 kharif. The resultant 55 single crosses and eleven parents were evaluated in 1994 in randomized block design with 3 replications. Each entry consisted of single row of 3m length. The row to row and plant to plant distances were 30 cm and 5-7 cm respectively. Standard agronomical practices were followed to raise the crop. Random 10 plants were harvested from each entry to assess fibre yield. Data on fibre yield were subjected to diallel analysis following Model 1, Method 2 of Griffing [1].