To evaluate the efficiency of anther floating culture according to the maturing group, the varietal difference and classification of fifty varieties was conducted in N6 liquid medium containing 1mg l-1 NAA, 0.25 mg l-1 kinetin. The efficiency of callus induction was widely ranged from 0 to 113.4%, but the mean callus induction was not significantly different among maturing groups. The efficiency of anther floating culture showed the highest variation in early-maturing group among three maturing groups. The varieties with the best callus induction were Sambaegbyeo and Jinbuolbyeo, while the recalcitrant variety was Obongbyeo in early-maturing group. The efficiency of plant regeneration showed the highest trends in late-maturing group among three maturing groups. The fifty varieties were classified into three groups (distance=0.78) by cluster analysis based on the callus formation and plant regeneration. Group including only two varieties, Shinunbongbyeo and Sambaegbyeo had the excellent androgenic efficiency, and the medium efficiency of Group was included thirty-six varieties. Whereas twelve varieties, including three Tongil varieties were fell into the bad efficiency of Group. Especially, Tongil varieties containing Japonica rice, Obongbyeo were the recalcitrant genotypes for the anther floating culture.

The performance of 7 sugary (su) and 12 shrunken-2 (sh2) sweet com hybrids which are commercially grown in the United States was tested in Korea. The 100-seed weight of su hybrids (16.5-23.6 g) was much heavier compared to that of sh2 hybrids (10.9-17.5 g). The germination rate of su and sh2 hybrids at 25~circC ranged 93.3-100% and 86.7-98.9%, the emergence rate of su and sh2 hybrids in cold test ranged 78.9-97.8% and 62.2-97.8%, and field emergence rate of su and sh2 hybrids ranged 74.4-100.0% and 79.9-98.2%, respectively. In su hybrids, there was a significantly positive correlation between germination rate at 25~circC and emergence rate in cold test or early growth. In contrast, in sh2 hybrids seed weight was positively correlated with early plant growth, while not with the germination rate at 25~circC or emergence rate in cold test and field. Most sh2 hybrids produced larger and more marketable ears compared to su hybrids although there were significant differences among the hybrids in the same genotype. At harvest (24 days after pollination) soluble solids content of su hybrids (24.3-27.1 Brix %) was much higher than that of sh2 hybrids (13.8-18.0 Brix %), while total sugars of sh2 hybrids (21.4-28.6% on the dry weight basis) was much higher compared to su hybrids (2.4-15.9%). Considering germination and emergence rates, marketable ear production, and total sugar content, 'GCB 70' and 'Sweet Satin' in su hybrids and 'Ice Queen', 'Aspen', 'Sweet Magic', 'Bandit', 'Xtrasweet 82', 'Aspen', and 'Cambella 90' in sh2 hybrids performed better than other hybrids.