• 한국작물학회:학술대회논문집
• /
• 한국작물학회 2017년도 9th Asian Crop Science Association conference
• /
• pp.103-103
• /
• 2017

Vigorous root growth at the seedling stage in dry direct-seeded conditions is considered as a critical trait because it is involved in seedling emergence, early vegetative vigour, nutrient uptake as well as drought tolerance. In this study, we performed QTL mapping using the recombinant inbred lines obtained from the cross between Tongil-type Dasan and temperate japonica TR22183 (DT-RILs) to identify QTL underlying early root development. TR22183, which was previously reported to have high nitrogen utility and cold tolerance, showed vigorous root growth at the seedling stage in semi-drought conditions. Root length, fresh weight and dry weight of TR22183 were significantly higher than in Dasan. By QTL analysis with genotyping-by-sequencing method, we identified two QTLs for root fresh weight (RFW) in chromosome 7 and root dry weight (RDW) in chromosome 8, explaining phenotypic variances of 13.5% and 10.6%, respectively. These QTLs would be used to develop rice varieties adapted to direct-seeded cultivating system.

• 생물환경조절학회지
• /
• 제11권1호
• /
• pp.35-39
• /
• 2002

본 연구는 엽채류 육묘시 $CO_2$시용이 정식 후 $CO_2$의 장기 시용으로 인한 청경채, 시금치 및 상추의 생육에 미치는 영향을 조사하였다. 육묘시 $CO_2$시용은 청경채, 시금치 및 상추의 지상부 생체중과 건물중 및 엽면적에서 모두 무처리구에 비해 현저히 증가하였는데, 생체중의 경우 처리구에서 각각 50%, 60% 및 30%내외의 증가를 나타내었다 뿌리 건물중은 시금치 및 상추에서 무처리구에 비해 처리구에서 현저히 증가하였다. 무처리구에 대한 지상부 생체중의 상대증가율은 청경채, 시금치 및 상추에서 공히 $CO_2$시용 10일 전후에서 가장 높았다. 정식후 $CO_2$시용 효과를 육묘시 $CO_2$를 시용한 처리구와 시용하지 않은 대조구로 구분하여 비교한 결과, 엽면적은 청경채, 시금치 및 상추에서 모두 처리구가 대조구에 비해 20%내외의 증가를 보였다. 지상부 생체중과 건물중은 처리구에서 3작물 모두 10~20%범위의 증가효과를 보였는데, 이는 육묘기의 30-60%의 증가효과에 비해 크게 둔화된 것으로 나타났다. 잎의 광합성속도는 정식 후 대조구에서 완만하게 감소하는데 비해 CO2를 장기 시용한 처리구에서는 급격히 감소하는 경향을 보였다.

• 한국작물학회지
• /
• 제44권3호
• /
• pp.236-242
• /
• 1999

To examine the seedling stand and growth as affected by early seeding dates of dry direct seeded rice in the Honam plain area of Korea, Dongjinbyeo was seeded at six seeding dates from early March to late April in rice fields of silty loam soil(Jeonbuk series) at the National Honam Agricultural Experiment Station (NHAES) for two years, 1996 and 1998. Seedling stand decreased slightly. with an early seeding date, but it produced more than the optimum seedling number except for the seeding of 25 March in 1996. Days to emergence was significantly longer, as seeding date was earlier, and days to emergence by early seeding was shortened only by 8 days because the mean air temperature was lower in 1996 than average, while in 1998, the reduction effect was nine to twenty five days because the mean air temperature was higher than average. In early seeding, various weeds occurred at the emergence date of rice and dominant weeds were Alopecurus aequailis, Ludwigia prostata and Rorippa islandica. NH$_4$$^{+}$ -N content in the soil at the 5th leaf stage and maximum tillering stage were lower, as the seeding date was earlier when nitrogen was split applied as basal and top dressed in 1996, while it was not significantly different among seeding dates when nitrogen was intensively applied as a top dressing in 1998. Tiller number at the maximum tillering stage and panicle number/m$^2$ were more, as seeding date was earlier in 1996, while it was not different in 1998. Filled grain rate and 1,000 grain weight was not different among the seeding dates. Milled rice yield was significantly decreased in the seeding before the middle of March, but in the seeding after late March, it was not varied when compared with the normal seeding date in 1996, while in 1998, there was no difference among seeding dates. From the above results, in consideration of seedling stand, weed occurance, rice growth and milled rice yield, the critical optimum early seeding time in the southern plain area may lie in early April. But it was suggested that when soil moisture is proper for seeding practices, seeding amount is increased and nitrogen is applied after plumule emergence of rice, milled rice yield may not be reduced in the seeding of middle or late March, compared with the seeding in April.l.

• 한국작물학회지
• /
• 제31권3호
• /
• pp.286-292
• /
• 1986

Saponin생합성의 개체발생학적 정보를 얻기 위하여 인삼종자의 개갑과정과 묘삼생육초기에 saponin및 유리당의 변화를 HPLC로 조사하있다. 개갑처리 40일 후에 약 80%의 saponin이 없어졌으며 Rc, Rb$_2$, Rb$_1$이 없어지고 PD가 더 많이 없어졌다. 70일 후에는 40일 후보다 증가하였으며 Rg$_2$와 Rg$_3$(추정), 20-gluco Rf(추정)의 증가는 분해용탈 외에 생합성 가능성을 배제하지 아니하였다. F$_3$(추정)는 과육에 없고 미숙배유와 배에 있고 개갑과정에서 적어졌다. Rg$_3$는 과육에 없고 배유와 배에 흔적으로 있으나 개갑에서 증가되었다. 20-gluco Rf는 개갑 중 배유와 배에서만 나타났다. 4월 20일의 묘삼근에서 saponin은 없었으나 줄기에서는 개갑시 보다 많았다. 근의 saponin 생성은 5월 29일에 나타났으나 6월 30일에야 Rc, Rb$_2$, Rb$_1$이 처음 생기며 본 궤도에 이르는 것 같다. 6월 중 단위 생중당 saponin 생합성 속도는 뿌리보다 잎에서 배가 높았다. 잎사포닌 F$_3$와 F$_{6}$가 뿌리에서 발견되고, 근 saponin Rg$_3$와 20-gluco-Rf가 엽에서 나타났으나 점점 감소하였다. Saponin함량의 변화에는 PD가 주역이여서 PT/PD는 saponin 함량과 부상관을 보였다. 재갑처리 70일에도 sucrose의 함량이 높았으나 glucose는 흔적, fructose는 없었다. 묘삼의 잎은 sucrose보다 glucose와 fructose가 초기에는 많았으나 후에는 상당히 적어졌다. 줄기는 glu-cose가 많고 기타는 흔적 정도 였으며 뿌리는 초기에 sucrose가 종자에서 보다 높았으나 그 후 모든 당이 거의 흔적뿐이었다.

• The Korean Journal of Ecology
• /
• 제15권3호
• /
• pp.297-309
• /
• 1992

The growth of digitaria adscendens and eleusine indica, annual weeds common in japan, was experimentally analyzed under varying untrient conditions. compared with e. indica, d. adscendensshowed a higher the two under high nitrogen availability. Higher net assimilation rate(nar) in d. adscendens than e. india was responsible for high RGR in D. adscendens under the low nitrogen availability. The different of NAR in the two species was induced not by leaf nitrogen content but by nitrogen use efficiency. Under unfertilized conditions nitrogen uptake rate(nur) was greater in d. adscendens than e. indica. Specific absorption rate in two species was similar, but root mass was greater in d. adscendens than e. indica.d. adscendens allocated more dry matter to roots than e. india earlier stage of seedlings. The contributed to higher rot mass and in turn resulted in higher nur in d. adscendens than that in e. india. It is concluuded that the larger allocation of dry matter to roots at early seedling stage in d. adscendens plays an important role in obtaining nitrogen for the continuation of growth under low nitrogen availability.

• 한국작물학회지
• /
• 제44권2호
• /
• pp.149-153
• /
• 1999

Prediction of rice developmental stage is necessary for proper crop management and a prerequisite for growth simulation as well. The objectives of the present study were to find out the relationship between the plastochrone index(PI) and the developmental index(DVI) estimated by non-parametric phenology model which simulates the duration from seedling emergence(DVI=0) to heading(DVI=l) by employing daily mean air temperature and daylength as predictor variables, and to confirm the correspondency of developmental indice to panicle developmental stages based on this relationship. Four japonica rice cultivars, Kwanakbyeo, Sangpungbyeo, Dongjinbyeo, and Palgumbyeo which range from very early to very late in maturity, were grown by sowing directly in dry paddy field five times at an interval of two weeks. Data for seedling emergence, leaf appearance, differentiation stage of primary rachis branch and heading were collected. The non-parametric phenology model predicted well the duration from seedling emergence to heading with errors of less than three days in all sowings and cultivars. PI was calculated for every leaf appearance and related to the developmental index estimated for corresponding PI. The stepwise polynomial analysis produced highly significant square-rooted cubic or biquadratic equations depending on cultivars, and highly significant square-rooted biquadratic equation for pooled data across cultivars without any considerable reduction in accuracy compared to that for each cultivar. To confirm the applicability of this equation in predicting the panicle developmental stage, DVI at differentiation stage of primary rachis branch primordium was calculated by substituting PI with 82 corresponding to this stage, and the duration reaching this DVI from seedling emergence was estimated. The estimated duration revealed a good agreement with that observed in all sowings and cultivars. The deviations between the estimated and the observed were not greater than three days, and significant difference in accuracy was not found for predicting this developmental stage between those equations derived for each cultivar and for pooled data across all cultivars tested.

• 한국잡초학회지
• /
• 제30권2호
• /
• pp.103-110
• /
• 2010

일년생 잡초인 물달개비 및 올챙이고랭이의 출아와 초기생장을 예측하기 위한 모델 구축을 위하여 온도조건을 달리한 식물생장상에서 포트실험을 수행하였다. 이들 잡초의 출아 및 초기생장과 유효적산온도와의 관계를 비선형회귀로 분석한 결과 온도조건에 상관없이 각각 Gompertz 모델 및 logistic 모델로 설명이 잘 되었다. 물달개비 및 올챙이고랭이의 최대 출아율의 50%에 필요한 유효적산온도는 각각 69.3 및 $94.8^{\circ}C$이었으며, 4엽기에 이르는데 필요한 유효 적산온도는 각각 247 및 $234^{\circ}C$이었다. 본 연구에서 개발된 모델로 분석한 결과 평균 기온이 $3^{\circ}C$ 상승하게 되면 이들 잡초의 50% 출아는 물달개비의 경우 1일, 올챙이고랭이의 경우는 2일 빨라지고, 4엽기에 다 다르는 날짜는 이들 잡초 모두 3일이 빨라질 것으로 예측되었다. 따라서 온도상승조건에서 물달개비 및 올챙이고랭이를 효과적으로 방제하기 위해서는 현재의 처리시기보다 약 2-3일 빨라져야 할 것으로 예상된다.

• 원예과학기술지
• /
• 제19권3호
• /
• pp.329-333
• /
• 2001

감자의 품종육성의 초기세대에서 플러그 육묘 선발법을 이용하여 정식과정을 생략하고 플러그 내에서 직접 계통을 선발하는 방법과 숙기판별 효과를 구명코자 일련의 시험을 수행하였다. 감자의 실생육묘를 위하여 105공, 200공 및 288공 플러그 트레이가 사용되었다. 플러그 트레이에서의 종자발아율은 94- 96%로 높았다. 플러그 규격별 괴경착생률은 종자 파종 후 50일과 60일까지는 105공에서 가장 높았고, 70일에는 200공에서 가장 높았으나 288공의 플러그 트레이에서는 가장 낮았다. 그러므로 괴경착생이 빠른 조생개체의 선발을 위해서는 플러그의 크기가 큰 105공이 효과적인 것으로 생각된다. 한편, 감자육종 초기세대의 플러그 육묘단계에서 복지의 형태에 따른 조.만생 개체의 선발효과를 구명코자 복지의 길이에 따라 숙기를 구분하였다. 1세대인 유묘단계에서 복지가 짧은 그룹은 2세대인 괴경 선발단계에서도 대부분 조생종으로 나타났고, 반면 복지가 긴 그룹은 대부분 만생종으로 구분되었다. 이상의 결과를 통하여 볼 때 감자육종 초기세대에서 플러그 육묘법은 복지의 형태적 특성 구분이 용이하여 감자의 숙기관련 형질선발에 효과적인 것으로 판단되었다.

• 한국작물학회지
• /
• 제47권4호
• /
• pp.286-291
• /
• 2002

Seedling establishment of soybean [Glycine max (L.) Merr.] is a critical factor in production system and cultural practices. The objective of this study was to identify the components of soybean seedling developments encompassing planting dates and cultivars that respond to emergence, early growth stage and dry matter accumulation. Three soybean cultivars, Hwangkeumkong, Shinpaldalkong 2, and Pungsannamulkong, were planted at Baegsan silty loam soil. Planting date was May 13, June 3, and June 24 in 2001. Sprinkler irrigation was accompanied with 30mm after seeding for three planting dates. Soybean seedlings were sampled at the growth stages from VE to V5. Days to emergence of soybean seedlings were taken 8 at May 13 and 5 at June 24 plantings. Emergence percentage was over 90 at three planting dates. May 13 planting took 33 days and June 24 planting was 25 days for reaching V5 growth stage. Cotyledon number was decreased after V2. Significant cultivar difference was found in cotyledon dry weight until V2 which differed in seed dry weights at the planting times. Leaf and total dry weights of soybean seedlings were not differed from V1 to V3 among planting dates and cultivars. Leaf water contents were generally ranged 78 to 85%. Branch was appeared from V4. Leaf/stem ratio among cultivars was similar at five growth stages and gradually increased from 2.1 at V1 to 2.8 at V5. The results based on this experiment indicated that seedling establishment of soybean was continued from VE to V3 growth stages affecting mainly by planting date and soil moisture.

• 한국환경복원기술학회지
• /
• 제18권3호
• /
• pp.79-95
• /
• 2015

To suggest ecological management plans for invasion of Salix gracilistyla, stepwise environmental sieve of seed dispersal, germination, seedling and juvenile stages were investigated. About 84% of total seeds were released between May 6 and 10. Germination rates significantly declined with decrease of light intensity from 100% to 30% and 0% (p<.001), but above 60% of seeds germinated in all treatments. Difference of germination rates with 0 and 2cm water level was not significant (p = .571). With increase of elapsed time after seed dispersal, germination rates significantly decreased (p<.001), and seed viability was lost within 16 days. Considering both germination rate of seed and survival rate of seedling, survival rate of all dispersed seeds was only 5% when 8 days passed after seed dispersal. All 22-day-old seedlings (height: 1cm) died under flooding of twice level as its height. With decrease of light intensity from 100% to 30%, survival rates of seedling decreased from 90% to 33% (p<.001). In the case of 45-day-old juvenile (height: 20cm), survival rate was 70% under the water level same as its height. There was significant interactive effect of water level and light intensity on the growth of juvenile (height: p<.001, dry weight: p<.01), and survival rate of juvenile was 10% under +20cm-water level and 30%-light intensity condition. The following management plans for invasion of S. gracilistyla are recommended from these results. (1) Dry condition should be maintained at fringe of wetlands for about two weeks at seed dispersal and germination stage (early May~mid May). (2) Water level should be raised to about 5cm at fringe of wetlands for about two weeks at seedling stage (mid May~early June). (3) Water level should be raised to over 20cm at fringe of wetlands for a long time at juvenile stage. Planting trees for shading can raise management effectiveness (mid June~). (4) As water level manipulating is performed as fast as possible for controlling seedling and juvenile, management become easier and more effective.