발아기를 전후한 이상기후로 감나무의 신초 생장이 늦어지는 경우가 많다. 본 연구는 봄철의 생장 지연이 ‘부유’의 신초 및 과실 생장에 미치는 영향을 파악하고자 수행되었다. 신초 생장 지연을 유도하기 위해 탈순화 과정에 있는 눈의 온도조건을 달리하였는데, 발아 전인 3월 12일부터 정상 나무의 발아3일 후인 4월 8일까지 3~4년생 측지에 폴리에틸렌 비닐주머니를 씌우는 방법으로 하였다. 비닐주머니를 설치했던 가지는 낮 온도가 2~5℃ 높아진 반면 밤 온도는 외기온과 같아 주야간 온도변화 폭이 커졌고, 그 결과 4월 동안 발아와 신초 생장 지연 정도가 달라졌다. 4월 27일에 길이 0.5~10 cm 범위의 신초를 30개 선정하여 길이를 측정하고 각각의 생장을 추적 조사하였다. 생장 지연이 심한 신초일수록 개화가 늦어 7일까지 차이가 있었고 엽장이 짧아졌으나 신장이 종료된 신초장은 차이가 없었다. 신초 생장 및 개화가 지연될수록 수확 과실의 크기가 작아진 반면, 색도, 경도, 당도는 유의적인 변화가 없었다.

‘Migamjosaeng’ (Diospyros kaki Thunb.) is a new pollination-variant non-astringent type (PVNA) persimmon cultivar developed by Sweet Persimmon Research Institute of Gyeongnam Agricultural Research & Extension Services. This cultivar was selected among the seedlings obtained from the cross between ‘Mazumotowase-Fuyu’ and ‘Nishimurawase’ in 1995. The seedlings were cultivated from 1996 to 2001 and ‘Migamjosaeng’ was selected in 2002. The tree growth habit and fruit characteristics of ‘Migamjosaeng’ were investigated from 2004 to 2007. The tree growth habit was moderate vigor and showed spreading shape. Flowers bloomed only in female flowers. The flowering time was similar to that of ‘Nishimurawase’ (control) in late May, but the harvest time was about 3 days earlier than ‘Nishimurawase’ in late September. ‘Migamjosaeng’ is characterized by its beautiful orange skin color with round flat shape of fruits. Average fruit size was about 160g. Soluble solids were 16.6°Brix and higher than that of control (14.5°Brix), which contributed to its excellent tastiness. It was noteworthy that occurrence of calyx-end cracked fruits and striped fruit was very rare compared with the control. Therefore, ‘Migamjosaeng’ trees produced marketable fruits much higher than the control tree. Flesh firmness was slightly high and similar to ‘Nishimurawase’.

‘수안’은 국립식량과학원 벼맥류부에서 2010년에 육성한 고품질 직파적응 내도복 복합내병성 품종이다. ‘수안’의 출수 기는 담수직파에서 8월 15일로 ‘주안벼’보다 1일 늦으며, 보통기 보비 이앙재배에서는 평균 출수기가 8월 10일로 ‘남평 벼’보다 6일정도 빠른 중생종이다. 간장은 담수직파에서 74 cm로 ‘주안벼’보다 4 cm 크고 이앙재배에서는 ‘남평벼’와 비 슷하며 담수직파시 m 2당 수수와 수당립수는 ‘주안벼’보다 적 고 등숙비율이 높으며, 현미천립중은 25.4 g으로 ‘주안벼’보 다 무겁다. 내냉성 검정에서 유묘적고는 ‘남평벼’와 비슷한 반응을 보였고, 출수지연일수가 ‘남평벼’에 비해 2일 정도 길 으나 임실률은 47%로 ‘남평벼’에 비해 높은 편이다. 등숙기 수발아율은 22%로 ‘남평벼’보다 높고 포장도복은 강한 편이 다. 도열병, 흰잎마름병(K1～K3) 및 줄무늬잎마름병에 저항 성이나 기타 바이러스병 및 벼멸구류 등의 해충에는 저항성 이 없다. 단원형이며 쌀 외관은 심복백이 없고 ‘남평벼’ 수준 으로 맑고 투명하다. 단백질 함량 및 아밀로스 함량은 각각 6.5% 및 19.5%이며 밥맛은 ‘남평벼’ 수준이다. 제현율, 도정 율은 ‘남평벼’보다 다소 높으나 백미완전립률은 낮은 편이었 다. 쌀 수량성은 담수직파 6개소 및 건답직파 4개소에서 각각 5.47 MT/ha, 5.56 MT/ha로 ‘주안벼’보다 9% 증수 되었으며, 보통기 보비재배에서는 5.80 MT/ha으로 ‘남평벼’ 대비 4% 증수하였다.

총 22개의 감 SSR primer set을 사용하여 주요 재배품종 17품종, 수집한 단감 변이개체 13종 등, 총 30개의 유전적 연관성을 분석하였다. 획득한 469개의 다형성 밴드를 이용하여 UPGMA 방식으로 유사도 및 집괴분석을 수행한 결과, 30개의 품종 및 수집 계통들은 크게 2개의 그룹(cluster)으로 나뉘어졌으며, 제 1 cluster는 다시 3개의 subcluster로, 제 2 cluster는 다시 2개의 subcluster를 형성하였다. 이는 수집 계통들이 기존 대조품종들과 서로 동일군으로 분포되고 있어 형태적으로 유사할 수 있고 근연되어 있지만, 유전자적 수준에서는 다른 조성을 가지고 있음을 보여준다. 평균 유사도의 값은 0.164 이였고 품종간 가장 높은 유사도 값(0.31)을 나타낸 것은 ‘차랑’과 ‘전천차랑’이였고, 가장 낮은 유사도 값(0.02)를 나타낸 것은 Ⅱ 그룹과 비교하여 Ⅰ 그룹에 속하는 ‘Rojo Brillante’였다. 본 연구에 사용된 22 SSR primer set을 통해, ‘차랑’과 ‘전천차랑’을 제외한 대조품종과 수집 계통간의 구별이 가능하여 향후 신품종 개발시 품종보호를 위한 특이적 마커로 효율적으로 사용될 수 있을 것으로 판단된다.

The amount of salt to make seed sorting solution of the specific gravity of 1.13 was reconsidered and determined as 3.8 kg salt in 18 L water, which is lower amount than currently used. Five rice cultivars were examined. Percent germination and seedling emergence were not similar. Seedling emergence rate of Japonica varieties, Nampyungbyeo and Daerypbyeo-1 were 87% and 95% under specific gravity of 1.13, respectively. Seedling emergence rate of Tongil type variety, Dasanbyeo was as high as 67% in specific gravity of 1.06. Seedling emergence rate of waxy rice, Hwasunchalbyeo and Aranghangchalbyeo were examined. Seedling emergence rate was 94% in both cultivars in specific gravity of 1.04. Seedling emergence rate was same in specific gravity of 1.08 which is generally used for selecting seed currently. Early growth (plant height, leaf number, and dry weight) were not significantly different by specific gravity within species. In all cultivars except waxy rice, highest seedling emergence rate was observed in specific gravity of 1.13 which is currently used for selection and decreased as specific gravity is lowed. However, considering total amount of seeds in each group of specific gravity, amount of seed in lower specific gravity group is relatively small and total seedling emergence rate within variety dose not show big difference. However, if seeds with low speicific gravity are produced due to the bad grain filling condition and consequently total seed content of low specific gravity increases, results will be differnt. Reduction in total growth and yield could occur. It will be important to comply with the seed sorting criterion of 1.13 for Japonica, 1.06 for Tongil, and 1.04 for waxy rice variety to ensure the maximum rice growth and yield.

Rice seeds germinate in the complete absence of oxygen. Under anoxia, the seeds have greater stress in abiotic condition than in aerobic one. Antioxidant enzymes play an important role of ROS(Reactive Oxygen Species) scavenging in various anoxic stress. We investigated the relationship between antioxidant enzymes and early seedling growth of four rice cultivars (Iksan 429, Khaiyan, FR13A, and Nampyeong) under anoxic and aerobic conditions. Rice seeds immersed into a sealed water bottle for 10 days. During anoxia, rates of cleoptile elongation were faster in tolerant varietise Iksan 429 and Khaiyan than in FR13A and Nampyeong. In the anoxic water condition, the activity of SOD in Iksan 429 and Khaiyan increased slightly until 5 days , while that of Nampyeong and FR13A decreased significantly after 7 days. The activity of peroxidase in Khaiyan was higher than that of FR13A. These results suggest that the ability to increase SOD and POX may be one of the determinants in anoxia tolerance of rice.

Hwangeumnodeul is a new japonica rice cultivar developed from a cross between Milyang165 and HR15151-B-21-3 at Honam Agricultural Research Institute (HARI), NICS, RDA, in 2007. This cultivar has short grains and about 139 days of growth duration from direct seeding to harvesting in the southern plain areas. Culm length of this cultivar is 78 cm and the number of spikelet per panicle is similar to that of the check cultivar, Nampyeongbyeo, while filled grain rate is lower than the check variety. This cultivar is moderately resistant to leaf blast, bacterial blight pathogens of K1, K2 and K3 and stripe virus but susceptible to major virus diseases and insect pests. Milled kernel of Hwanggeumnodeul is translucent with non-glutinous endosperm. This cultivar has about 5.7% and 18.6% of protein and amylose contents, respectively. Palatability of cooked rice of Hwanggeumnodeul is similar to Nampyeongbyeo. Its milling recovery and head rice were 75.6% and 90.0%, respectively. Hwanggeumnodeul yielded 5.69 and 5.61 MT/ha in milled rice at the under wet-direct and dry-direct seeding conditions, respectively which are 17% and 12% higher than the check variety, Juanbyeo. It yielded 5.86 MT/ha, 8% higher than Nampyeongbyeo at the standard fertilizer level of the ordinary transplanting cultivation. “wanggeumnodeul”would be adaptable for ordinary transplanting as well as direct seeding in the southern plain including Chungcheong province.