Indira Gandhi Agricultural University Raipur, India

In 1990 we reported on the genetic analysis of ARC5984 and concluded that this cultivar has a single recessive gene for resistance which was designated as gm3 (Sahu et a!. 1990). The seeds of this variety came from the germplasm being maintained at Indira Gandhi Agricultural University. Later we received seeds of another cultivar labelled ARC5984 from Directorate of Rice Research (DRR) Hyderabad. When we compared these two sources of ARC5984, we noticed that ARC5984 used in earlier study was short in stature, but ARC5984 received from DRR was a tall conventional variety. On further examination ARC5984 used in the earlier study (Sahu et al. 1990) was found to be very similar to RP2068-18-3-5, a short statured breeding line. Thus it seems that RP2068-183-5 was mislabelled as ARC5984 at Indira Gandhi Agricultural University. We therefore decided to carry out genetic analysis of RP2068-18-3-5 and ARC5984 from DRR. ARC5984 was crossed with gall midge susceptible parents Kranti and Shyamla. The F1 hybrids were resistant. The F2 progenies segregated in a ratio of 3 resistant to I susceptible. F3 families segregated in a ratio of 1 resistant to 2 segregating to 1 susceptible (Table 1). These data show that ARC5984 has a single dominant gene for gall midge resistance. ARC5984 was also crossed with Samridhi(Gml), Phalguna(Gm2) and Abhaya (Grn4). The F, hybrids were resistant as expected. The F2 populations segregated in a ratio of 15 resistant to 1 susceptible and F3 families segregated in a ratio of 7 resistant to 8