Centipedegrass는 미국 동남부지역에서 잔디용으로 많이 이용하고 있는데 토양을 가리지 않고 잘 자라며 잎이 연녹색이어서 잔디로서 선호도가 높다. 그러나 이 식물의 유전자원이 지니고 있는 유전변이 폭이 매우 한정되어 있어 활용 가능한 유전변이의 폭을 확대하기 위해 Centipedegrass의 종자에 감마선 10Kr을 조사한 뒤 계통을 조성하고 이를 다시 감마선 10Kr을 조사하여 계통을 조성하는형태로 순환 조사하여 순환 처리회수를 각각 0회, 4회, 5회, 6회, 8회 하여 얻은 계통집단 TC 201, TC 202, TC 241, TC 306, TC 318에 대하여 이들 계통집단이 지니고 있는 식물 형태적 특성의 평균과 변이의 범위 폭을 측정하여 비교한 결과 이미 품종으로 고정되어 있는 TC318을 제외하고 감마선을 종자에 순환처리한 계통집단에서 총지하경수, 총지하경길이, 최장지하경장, 엽장 및 엽폭의 변이폭이 감마선 조사로 확대되었음을 확인하였다. 이러한 변이의 범위 확대 정도는 지하경과 같은 생식기관에서 뚜렷하였는데 방사선 순환조사 정도와 관련하여 일정한 방향성은 인정되지 않았다.

‘Yuyeon’, a new ruminant-palatable barley cultivar, was developed from the cross between ‘Suwon311’ and SB86648〔CMB81A-2149 / Saeolbori // Buheung / Gangbori / 5 / Bera-olbori / Horisee-Buheung // bengei / 3 / Olbori-Daechi-Hagane / 4 / T.beared〕by the Honam Agricultural Research Institute (HARI), NICS, RDA in 2006. Among the cross made in 1996, a promising line, SB961012-B-B-1, showed good characteristics in potential forage yield in the yield trial tested in Suwon in 2001. In 2004, it was designated as ‘Suwon 406’ and placed in regional yield trials at five locations around Korea for three years from 2004 to 2006, and was released as the name of ‘Yuyeon’. It belong to maturity group Ⅲ and shows erect leaf type and compact spike with types of hoods. Its heading date was Apr. 27, which was 2 days earlier than that of the check cultivar ‘Olbori’ (‘Sunwoo’), and early dough stage, which was May. 30 which was same date of that of the check cultivar. ‘Yuyeon’ showed weaker winter hardiness, but better resistance to lodging, shattering and BaYMV than those of check cultivar. It showed higher crude protein content, grade of silage quality than those of check cultivar. The average forage yield in the regional yield trial was 10.47 MT/ha, which was 1% lower than that of the check cultivar. Cattles fed with silage from ‘Yuyeon’ (hood type) showed higher feed concentrate requirement (12.9 kg/day/body) and daily weight gain (1.46 kg/day) than those of cattles fed with silage from ‘Olbori’ (rough awn). This cultivar would be suitable for the area whose daily minimum temperature was above -8℃ in January in Korean peninsula.

A ruminant-palatable barley cultivar, Soman (Hordeum vulgare L.), with early maturing, high silage quality and high yield, was developed from the cross between SB79124〔Bengei-Ginomeo-Buheung-Morsen-Hagane/Gangbori〕and SB77189 〔Samjug/Riso82//Olbori〕in 1994. A promising line “SB941067-B-B-B-45” was selected in 1998. It performed well in the preliminary and advanced yield trials for two years from 2002 to 2003. The line was designated ‘Suwon 404’ through the regional yield trials (RYT) at six sites for three years from 2004 to 2006. Its growth habit was winter type (Ⅲ) with greenish leaves, medium culm and compact density of spike setting. Its heading date and early dough stage were Apr. 23 and May 26 respectively, which were 6 days earlier than those of check cultivar ‘Olbori’. ‘Soman’ showed weaker winter hardiness, but better resistance to lodging, shattering, and BaYMV (Barley yellow mosaic virus) than those of check cultivar ‘Sunwoo’. It showed 1.7% higher TDN content on whole-crop-silage than that of check cultivar ‘Sunwoo’. Its average of forage yield in regional yield trials was 10.31 MT/ha, which was 4% higher than that of the check cultivar.