근관장 측정에 있어서 디지털 영상 처리기와 주파수 의존형 측정기의 정확도

이병립,박창서,Lee Byaung-Rib,Park Chang-Seo 대한영상치의학회 1998 Imaging Science in Dentistry Vol.28 No.2

In order to achieve a successful endodontic treatment, root canals must be obturated three-dimensionally without causing any damage to apical tissues. Accurate length determination of the root canal is critical in this case. For this reason, I've used the conventional periapical radiography, Digora/sup (R)/(digital imaging system) and Root ZX/sup (R)/(the frequency dependent type apex locator) to measure the length of the canal and compare it with the true length obtained by cutting the tooth in half and measuring the length between the occlusal surface and the apical foramen. From the information obtained by these measurements, I was able to evaluate the accuracy and clinical usefulness of each systems. whether the thickness of files used in endodontic therapy has any effect on the measuring systems was also evaluated in an effort to simplify the treatment planning phase of endodontic treatment. 29 canals of 29 sound premolars were measured with #15, #20, #25 files by 3 different dentists each using the periapical radiography. Digora/sup (R)/ and Root ZX/sup (R)/. The measurements were then compared with the true length. The results were as follows: 1. In comparing mean discrepancies between measurements obtained by using periapical radiography(mean error: -0.449±0.444 mm), Digora/sup (R)/(mean error: -0.417±0.415 mm) and Root ZX/sup (R)/(mean error: 0.123±0.458 mm) with true length. periapical radiography and Digora/sup (R)/ system had statistically significant differences(p<0.05) in most cases while Root ZX/sup (R)/ showed none(p>0.05). 2. By subtracting values obtained by using periapical radiography, Digora/sup (R)/ and Root ZX/sup (R)/ from the true length and making a distribution table of their absolute values. the following analysis was possible. In the case of periapical film. 140 out of 261<53.6%) were clinically acceptable satisfying the margin of error of less than 0.5 mm. 151 out of 261 (53,6%) were acceptable in the Digora/sup (R)/ system while Root ZX/sup (R)/ had 197 out of 261(75.5%) within the limits of 0.5mm margin of error. 3. In determining whether the thickness of files has any effect on measuring methoths, no statistically significant differences were found(p>0.05). 4. In comparing data obtained from these methods in order to evaluate the difference among measuring methods, there was no statistically significant difference between periapical radiography and Digora/sup (R)/ system(p>0.05), but there was statistically significant difference between Root ZX/sup (R)/ and periapical radiography(p<0.05). Also there was statistically significant difference between Root ZX/sup (R)/ and Digora/sup (R)/ system(p<0.05). In conclusion, Root ZX/sup (R)/ was more accurate when compared with the Digora/sup (R)/ system and periapical radiography and seems to be more effective clinically in determining root canal length. But Root ZX/sup (R)/ has its limits in determining root morphology and number of roots and its accuracy becomes questionable when apical foramen is open due to unknown reasons. Therefore the combined use of Root ZX/sup (R)/ and the periapical radiography are mandatory. Digora/sup (R)/ system seems to be more effective when periapical radiographs are needed in a short period of time because of its short processing time and less exposure.

근관장 측정에 있어서 디지탈 영상 처리기와 주파수 의존형 측정기의 정확도

이병립,박창서 大韓口腔顎顔面 放射線學會 1998 Imaging Science in Dentistry Vol.28 No.2

In order to achieve a successful endodontic treatment, root canals must be obturated three dimensionally without causing any damage to apical tissues. Accurate length determination of the root canal is critical in this case. For this reason, I've used the conventional periapical radiography, Digora(digital imaging system) and Root ZX(the frequency dependent type apex locator) to measure the length of the canal and compare it with the true length obtained by cutting the tooth in half and measuring the length between the occlusal surface and the apical foramen. From the information obtained by these measurements, I was able to evaluate the accuracy and clinical usefulness of each systems, whether the thickness of files used in endodontic therapy has any effect on the measuring systems was also evaluated in an effort to simplify the treatment planning phase of endodontic treatment. 29 canals of 29 sound premolars were measured with #15, #20, #25 files by 3 different dentists each using the periapical radiography, Digora and Root ZX. The measurements were then compared with the true length. The results were as follows: 1. In comparing mean discrepancies between measurements obtained by using periapical radiography(mean error : -0.449±0.444 mm), Digora (mean error : -0.417±0.415 mm) and Root ZX(mean error : 0.123±0.458 mm) with true length, periapical radiography and Digora system had statistically significant differences(p<0.05) in most cases while Root ZX showed none(p>0.05). 2. By subtracting values obtained by using periapical radiography, Digora and Root ZX from the true length and making a distribution table of their absolute values, the following analysis was possible. In the case of periapical film, 140 out of 261(53.6%) were clinically acceptable satisfying the margin of error of less than 0.5 mm, 151 out of 261(53,6%) were acceptable in the Digora system while Root ZX had 197 out of 261(75.5%) within the limits of 0.5 mm margin of error. 3. In determining whether the thickness of files has any effect on measuring methods, no statistically significant differences were found(p>0.05). 4. In comparing data obtained from these methods in order to evaluate the difference among measuring methods, there was no statistically significant difference between periapical radiography and Digora system(p>0.05), but there was statistically significant difference between Root ZX and periapical radiography(p<0.05). Also, there was statistically significant difference between Root ZX and Digora system(p<0.05). In conclusion, Root ZX was more accurate when compared with the Digora system and periapical radiography and seems to be more effective clinically in determining root canal length. But Root ZX has its limits in determining root morphology and number of roots and its accuracy becomes questionable when apical foramen is open due to unknown reasons. Therefore the combined use of Root ZX and the periapical radiography are mandatory. Digora system seems to be more effective when periapical radiographs are needed in a short period of time because of its short processing time and less exposure.

The changes of root length and form in immature teeth after orthodontic treatment

Kim,Hyeon-A,Park, Soo-Byung 대한치과교정학회 2004 대한치과교정학회지 Vol.34 No.3

교정치료에 대한 인지도 변화 및 보호자의 관심증가로 조기에 내원하는 환자가 많으며 그 중 일부가 전치부 치근첨이 완성되기 전인 10세 이전에 고정식 교정장치가 필요하게 된다. 따라서 본 연구에서는 미완성 치근의 치료 전후 치근의 길이 변화를 측정하고 형태변화를 관찰하여 완성된 치근의 교정력에 의한 변화양상과 비교하고, 환자의 성별, 기간, 이동양상 등과의 연관성을 조사하였다. 상악의 전치부 치근첨이 완성되지 않은 상태에서 고정식 교정치료를 시작한 8~10세 환자 28명을 실험군으로 하고, 치근첨이 완성된 상태에서 고정식 교정치료를 시작한 11~15세 환자 31명을 대조군으로 삼았다. 상악 4전치의 치료 전후 치근단 방사선사진상에서 치관, 치근길이를 측정해서, 치근길이의 변화량, 치관/치근 비의 변화량을 계산했고 분류체계에 따라 치근형태에 점수를 부여했다. 결과는 다음과 같다. 1. 대부분의 미완성 치근은 교정치료 후에도 치근 길이가 증가하였으며 정상적인 치근첨 형태를 보였다. 2. 치료기간이 길어지거나 개방교합의 경우, 미완성 치근이라도 치근길이가 증가하지 않거나 더 짧아진 경우도 있었으며 정상적인 길이가 되더라도 치근첨의 완성 형태가 뭉툭한 흡수 형태를 보였다. 3. 완성치근에서는 교정치료에 의하여 대부분의 치근이 경미한 치근흡수를 보였으며, 흡수된 치근첨의 형태는 미완성 치근의 완성 형태보다 더 뭉툭하였다(p<0.05). 4. 미완성 치근에서는 치료기간과, 완성치근에서는 치아의 이동거리(Ul to facial plane의 변화량)와 유의한 상관관계를 보였다(p<0.05). 5. 미완성 치근, 완성치근 모두 성별. 부정교합 분류, 수직피개의 변화량, 두개저에 대한 치아의 위치 변화(U1 to SN의 변화량)등과는 유의한 상관관계를 보이지 않았다. Previous studies have focused on the causes of root resorption after orthodontic treatment and treatment methods to reduce this phenomenon, and have been mainly associated with developed, mature roots. As parents become increasingly interested in their children's' dentition, orthodontists are performing fixed orthodontic treatment on patients of less than 10 years and before the completion of the immature root. Thus, the author evaluated the changes of root length and root form of maxillary immature incisors after orthodontic treatment, compared with those of mature teeth, and investigated the correlation according to gender, treatment duration, and displacement of incisors. The sample consisted of an immature root group of twenty-eight persons (between 8 and 10 years old) and a mature root group of thirty-one persons (between 11 and 15 years old). The crown and root length of the maxillary four incisors were measured with a periapical radiograph, changes in root length and crown-root ratio were calculated, and root form was classified according to a scoring system. The results were as follows. 1. The development of immature roots was not affected by orthodontic treatment and mostly showed normal root length and apical form. 2. Root length of immature teeth was sustained or became shorter, partially in long treatment duration or with open bite patients. Even though the teeth reached their normal root length, they demonstrated a blunt form. 3. Most of the mature roots showed mild resorption, and the form of mature roots was more blunt than the developed form of the immature roots (p<0.05). 4. The developed form of the immature roots was statistically related to treatment duration, while the form of the mature roots was significantly related to the displacement of incisors (p<0.05). 5. In contrast, other variables such as gender, classification of malocclusion, changes in overbite, and changes of U1 to SN showed no correlation with the root resorption of both groups.

국내 밀 품종의 유묘기 뿌리 특성과 초엽 길이 및 종자 특성 간 상관 분석

김경민,홍수민,최명구,최창현,이명희,윤미라,강천식,장기창,모영준,박철수 한국육종학회 2024 한국육종학회지 Vol.56 No.2

To stably produce domestic wheat under water-scarce environmental conditions due to climate change, root characteristics with excellent water utilization rates are crucial. In this study, we analyzed the root and grain phenotypes of 37 domestic wheat varieties over a two-year period by combining the results of genetic mutations related to semi-dwarfing and grain size. Root length was positively correlated with maximum root depth (r=0.76**) and total seminal root length (r=0.54**), whereas it was negatively correlated with the number of roots (r=-0.33**) and root angles (r=-0.51**). The thousand-kernel weight was positively correlated with embryo width (r=0.34**) and embryo area (r=0.33**) but was not correlated with other root traits. Embryo length was positively correlated with the number of roots (r=0.34**) and coleoptile length (r=0.42**). Phenotypic analyses of roots and grains, along with genotypic analyses of semi-dwarfing (Rht-B1 and Rht-D1) and grain size (TaCWI-4A, TaCWI-5D, TaGW2-6A, TaSus2-2B) genes, revealed that the Rht-D1b genotype led to reduced root depth, increased root angles, and reduced coleoptile length. TaCwi-A1, TaCWI-5D, TaSus2-2B, and TaGW2-6A, possessing the alleles TaCwi-A1a, Hap-5D-C, Hap-L, and Hap-6A-G associated with a larger grain size, resulted in an increased number of roots and root depth. Domestic wheat varieties were categorized into three clusters based on root, grain, and coleoptile trait characteristics, with 15 varieties in Cluster I, 9 in Cluster II, and 13 in Cluster III. The results of this study can be utilized in basic research to develop varieties that can produce stable domestic wheat by selecting resources with excellent root growth and seed characteristics.

국화 ‘백마’의 플러그 육묘시 삽목조건이 삽목묘와 절화 생육에 미치는 영향

유용권(Yong Kweon Yoo),노용승(Yong Seung Roh) 한국원예학회 2012 원예과학기술지 Vol.30 No.1

This study was carried out to examine the effect of cutting condition on the growth of rooted cuttings and their subsequent growth of cut flower in plug cutting of Dendranthema grandiflorum ‘Baekma’. The more leaves were attached to the cutting, the higher shoot growth of rooted cutting was observed. Cutting with two to six leaves was effective in shoot growth and rooting than any other treatment. Shoot growth of rooted cutting was not affected by cutting length, but rooting was better in 5 to 7 cm long cutting. Shoot growth and rooting of rooted cutting was promoted by increasing the cutting diameter, and rooting was better in 3.6-4.2 ㎜ thick cutting than 3.1 ㎜ thick cutting. As the treating concentration of NAA increased, shoot growth was inhibited and root length shortened in rooted cutting. Soaking with 100 ㎎ㆍL?¹ α-naphtalene acetic acid (NAA) for 1 h was effective in shoot growth and rooting. Root growth such as root number, root length, and root weight was better in rooting medium mixed with 2:2 of peatmoss:perlite than the other treatments. When rooted cutting produced from cutting with four or six leaves was planted, better length, weight, and leaf number of cut flower was observed. In rooted cutting produced with 7-9 ㎝ long cutting, growth of cut flower such as length, weight, and ray flower number was more effective than the others. Therefore, it is recommended that the 7 ㎝ long and 3.6 ㎜ thick cutting with four to six leaves is used to improve their rooting and subsequent growth of cut flower in plug cutting of Dendranthema grandiflorum ‘Baekma’.

근광장 측정에서 방사선 사진술의 정확도

조은영,박창서,Jo Eun-Young,Park Chang-Seo 대한영상치의학회 1998 Imaging Science in Dentistry Vol.28 No.2

For the successful endodontic treatment, root canal should be cleaned thoroughly by accurate mechanical and chemical canal preparation and sealed completely with canal filling material without damaging the periapical tissues. The accuracy of the root canal length measurement is a prerequisite for the success of the endodontic treatment, and the root canal length is often determined by the standard periapical radiographs and digital tactile sense. In this study, the accuracy and the clinical usefulness of Digora/sup (R)/, an intraoral digital imaging processor and the conventional standard radiographs were compared by measuring the length from the top of the file to the root apex. 30 single rooted premolars were invested in a uniformly sized blocks and No.25 K-file was inserted into and fixed in each canal. Each block was placed in equal distance and position to satisfy the principle of the bisecting angle and paralleling techniques and Digora/sup (R)/ system's image and standard periapical radiographs were taken. Each radiograph was examined by 3 different observers by measuring the length from top of the file to the root apex and each data was compared and analyzed. The results were as follows; 1. In the bisecting angle technique, the average difference between the Digora/sup (R)/ system and standard periapical radiograph was 0.002 mm and the standard deviation was 0.341 mm which showed no statistically significant difference between the two systems(p>0.05). Also, in the paralleling technique, the average difference between these two system was 0.007 mm and the standard deviation was 0.323 mm which showed no statistically significant difference between the two systems(p>0.05). 2. In Digora/sup (R)/ system, the average difference between the bisecting angle and paralleling technique was -0.336 mm and the standard deviation was 0.472 mm which showed a statistically significant difference between the two techniques(p<0.05). Also, in the standard periapical radiographs, the average difference between the bisecting angle and paralleling technique was 0.328 mm and the standard deviation was 0.517 mm which showed a statistically significant difference between these two techniques(p<0.05). 3. In Digora/sup (R)/ system and the standard periapical radiographs. there was a statistically significant difference between the measurement using the bisecting angle technique and the actual length(p<0.05), But there was no statistically significant difference between the measurement using the paralleling technique and the actuallength(p>0.05). In conclusion. the determination of the root canal length by using the Digora/sup (R)/ system can give us as good an image as the standard periapical radiograph and using the paralleling technique instead of the bisecting angle technique can give a measurement closer to the actual canal length. thereby contributing to a successful result. Also. considering the advantages of the digital imaging processor such as decreasing the amount of exposure to the patient. immediate use of the image. magnification of image size. control of the contrast and brightness and the ability of storing the image can give us good reason to replace the standard periapical radiographs.

여주 삽목 시 삽수절단 위치와 온도조건이 발근에 미치는 영향

이희주(Hee Ju Lee),이상규(Sang Gyu Lee),김성겸(Sung Kyeom Kim),최장선(Chang Sun Choi),김상범(Sang Beom Kim) (사)한국생물환경조절학회 2016 생물환경조절학회지 Vol.25 No.3

본 실험은 종자 가격이 비싼 여주를 삽목하여 증식하고자 할 때 적절한 줄기 절단위치와 삽목상내 온도를 구명하기 위하여 실험하였다. 시험품종 ‘NS454’(NS)와 ‘드레곤’(DR) 품종을 대상으로 삽수 절단 위치를 3번째 잎의 마디를 절단한 처리(I) 와 3번째와 4번째 잎의 중간부위를 절단한 처리(II)를 하였다. 삽목상내 온도는 18, 23, 28, 35℃ 처리를 하였다. 삽목상내 명기는 16시간유지하였으며, 광합성유효광량자속은 약 150-200μmol·m<SUP>-2</SUP>·s<SUP>-1</SUP> 정도였으며, 상대습도는 85% 이상 유지시켰다. 그 결과 삽목 후 10일에 생존율은 두 품종 모두 18℃와 23℃ 처리구에서는 삽수의 절단 위치와 상관없이 100%의 생존율을 보였지만, 18℃ 처리구의 경우, 뿌리 발근이 되지 않아 많은 개체가 고사하게 되었다. 뿌리 발근율에 있어서는 28℃ 처리구가 DR과 NS 품종 모두 삽수의 절단위치와 상관없이 100% 새뿌리가 발생하였고, 23℃ 처리구에서는 DR 품종의 경우 마디를 절단한 처리는 90%, 마디 중간지점을 절단한 처리는 40%이었으며 NS 품종의 경우도 마디를 절단한 처리는 50%, 중간지점을 절단한 처리는 40% 로 마디를 절단한 처리구에서 두 품종 모두 발근율이 높았다. 온도 35℃ 처리구에서는 발근율이 현저하게 낮아졌으며 NS 품종의 경우는 절단위치에 상관없이 발근이 되지 않았다. 뿌리의 개체당 발근수는 DR 품종의 경우, 28℃ 처리구는 마디 중간지점을 절단한 처리구에서 5.3개로 처리구중에서 가장 많았고 마디를 절단한 처리구는 2.7개이었다. 따라서 여주의 삽목시 절단위치는 마디부위를 절단하거나 마디 중간지점을 절단해도 되지만 마디 중간지점을 절단하는 것이 생존율을 높일 수 있을 것으로 사료되고, 또한 삽목상내 기온을 28℃ 정도를 유지해 주는 것이 바람직할 것으로 판단된다. This study was carried out to investigate proper stem cutting position and air temperature to regenerate roots from cuttings of bitter gourd. ‘NS454’ (NS) and ‘Dragon’ (DR) cultivars were tested and the cutting position was cut at the 3rd node in the stem (treatment I) and cut at the central part (stem segment) between 3rd leaf and 4th leaf in the stem (treatment II). The air temperature was maintained at 18, 23, 28 and 35℃ in the growth chambers, respectively. The photosynthetic photon flux at the ground of a chamber was maintained in approximately 150-200 μmol m<SUP>-2</SUP> s<SUP>-1</SUP> during the 16-hour photoperiod. The relative humidity in the chambers was maintained over 85%. After 10 days of cuttings, regardless of cutting position, DR and NS cultivars showed 100% the survival rate in the 18℃ or 23℃ treatments, however, most of plants 18℃ treatment had not rooting. In the 28℃ treatment, regardless of cutting position, DR and NS cultivars showed 100% of the rooting rate. In the 23℃ treatment, for DR cultivar, the node cutting showed 90% of rooting rate and the stem segment cutting showed 40% rooting rate. For NS cultivar, the node cutting showed 50% of rooting rate and the stem segment cutting showed 40% rooting rate. DR and NS cultivars have high rooting rate, while the rooting rate remarkably decreased in the 35oC treatment. For DR cultivar, the stem segment cutting showed 5.3 of the highest rooting number and the node cutting showed 2.7 rooting number in the 28℃ treatment. NS cultivar was not significantly different the rooting regardless of cutting position. The results suggested that cutting at the stem segment cutting of bitter gourd is an effective cutting method for increasing survival rate and the air temperature should be maintained at 28℃.

Laser 반사측정법을 이용한 전치부 후방 견인시 치조골 높이와 치근길이 감소에 따른 저항중심의 위치변화에 관한 연구

민영규,황충주 대한치과교정학회 1999 대한치과교정학회지 Vol.29 No.2

교정치료시 치아와 주위조직의 부작용을 최소로 하면서 최대의 치료결과를 얻기 위해서는 치료역학을 각 환자의 치아 및 주위 해부학적 환경에 맞도록 개인화 시켜야 한다. 특히 성인 교정시 문제되기 쉬운 치근흡수 또는 치주질환으로 인한 치조골 손실로 인하여 치관/치근 비율이 변했을 때 치아의 저항중심위치의 변화와 관련된 생역학적 반응의 차이에 주의하여야 한다. 본 연구에서는 정상 치주조직뿐만 아니라 다양한 비정상적 치주 및 치아상태에서 치관/치근 비율이 변하였을 때 일정한 교정력하에서의 치아의 초기이동 양상을 연구하기 위하여, 성인의 인체 건조 두개골 및 하악골상에서 laser 반사측정법 및 lever and pulley force applicator와 photodetector를 이용햐여, 상악 6 전치군을 대상으로는 치조골높이 를 가각의 치아에 대하여 2mm씩 총 8mm까지 감소시켰고, 하악 6전치군을 대상으로는 치근길이를 각각의 치아에 대하여 2mm씩 총 6mm까지 감소시키면서, 이렇게 다양하게 정량화된 변수들 하에서 상하악 6전치군으 저항중심의 위치변화를 연구한 결과 다음과 같은 결론을 얻었다. 1. 초기상태에서 상악6전치군의 초기이동시의 저항중심점의 위치는 6전치 전체 평균치아 치근의 치경부(CEJ)로 부터 치근첨 방향으로 약 42.4%되는 위치에 있었으며, 각 치아의 치조골의 높이가 감소할수록 저항중심점은 치근첨방향으로 약 76.7%되는 부위까지 이동하였다. 2.초기상태에서 하악 6전치군의 초기이동시의 저항중심점의 위치는 6전치 전체 평균 치조정으로부터의 거리는 치조골의 감소와 함께 지속적으로 감소하였으나, 치조골내의 평균 치근의 길이에 대한 비율은 치조골의 감소에 상관없이 약33%내외에서 비교적 일정하였다. 3. 초기상태에서 하악 6전치군의 초기이동시의 저항중심점의 위치는 6전치 전체 평균치아 치근의 CEJ로부터 치근점 방향으로 약43%되는 위치에 있었으며, 각 치아의 치근의 길이가 감소할수록 이 비율은 약54%까지 증가하였다. 그러나 CEJ로부터 저항중심점까지의 거리는 5.3mm전후로부터 3.3mm내외까지 감소하여 치근의 길이가 감소할수록 저항중심점이 CEJ방향으로 이동하였다. 4. 치조골 또는 치근흡수시, 각각의 단위 흡수량에 따른 저항중심위치의 변화에 미치는 영향은 초기에는 치조골이 감소 될 때가 더 컸으나 전체 평균 치근길이의 중간부위에서 영향은 비슷했다. Treatment mechanics should be individualized to be suitable for each patient`s personal teeth and anatomic environment to get a best treatment result with the least harmful effects to teeth and surrounding tissues. Especially, the change of biomechanical reaction associated with that of the centers of resistance of teeth should be considered when crown-to-root ratio changed due to problematic root resorption and/or periodontal disease during adult orthodontic treatment. At the present study, in order to investigate patterns ofinitial displacements of anterior teeth certain orthodontic force when crown-to-root ratio changed in not only normalperiodontal condition but also abnormal periodontal and/or teeth condition, the changes of the centers of resistance for maxillary and mandibular 6 anterior teeth as a segment were studied using the laser reflection technique, the lever & pulley force applicator and the photodetector with these quantified variables reducing alveolar bone 2mm by 2mm for each of maxillary 6 anterior teeth until the total amount of 8mm and root 2mm by 2mm for each of mandibular 6 anterior ones until the total amount of 6mm. The results were as follows: 1. Under unreduced condition, the center of resistance during initial displacement of maxillary 6 anterior teeth was located at the point of about 42.4% apically from cemento-enamel junction(CEJ) of the averaged tooth of them and kept shifting to about 76.7% with alveolar bone reduction. 2. The distance from the averaged alveolar crest level of maxillary 6 anterior teeth to the center of resistance for the averaged tooth of them kept decreasing with alveolarbone reduction, but the ratio to length of the averaged root embedded in the alveolar bone was stable at around 33% regardless of that. 3. Under unreduced condition, the center of resistance during initial displacement of mandibular 6 anterior teeth was located at the point of about 43% apically from CEJ of the averaged tooth of them and this ratio kept increasing to about 54% with root reduction. But the distance from CEJ to the center of resistance decreased from around 5.3mm to around 3.3mm that is to say, the center of resistance kept shifting toward C EJ with the shortening of root length. 4. A Unit reduction of a alveolar bone had greater effects on the change of the centers of resistance than that of root did during initial phase of each reduction. But both of them had similar effects at the middle region of whole length of the averaged root.

Effect of a Silicate Fertilizer Supplemented to the Medium on Rooting and Subsequent Growth of Potted Plants

Min Ji Bae,Yoo Gyeong Park,Byoung Ryong Jeong 한국원예학회 2010 Horticulture, Environment, and Biotechnology Vol.51 No.5

This experiment was carried out to examine the effect of a silicate fertilizer on the rooting of cuttings and subsequent growth of potted plants. Cutting of Kalanchoe blossfeldiana ‘Kaluna’ and ‘Taos’, and Dianthus caryophyllus L. ‘Kazan’ and ‘Tula’ were grown in 50 and 128-cell plug trays, respectively, containing a mixture of commercial medium and perlite (5:1, v/v). A silicate fertilizer [MgCa(SiO₃)₂] was supplemented at 0, 40, 80, 120 or 160 g?L<SUP>-1</SUP> medium. Silicate fertilizer supplementation at 40 g?L<SUP>-1</SUP> medium resulted in the greatest plant height, leaf width and length, length of the longest root, and root fresh and dry weights in both kalanchoe and carnation. However, medium supplemented with a silicate fertilizer at 120 g?L<SUP>-1</SUP> medium had reduced plant height, length of the longest root, and fresh and dry weights of roots. According to the scanning electron microscope images of transversal sections of tissues of roots in kalanchoe and carnation, the treatment of a silicate fertilizer supplementation at 40 g?L<SUP>-1</SUP> medium resulted in plants with more compact tissue than the control.

Polyethylene Glycol Induced Osmotic Stress Affects Germination and Seedling Establishment of Wheat Genotypes

Shatabdi Ghosh,Md. Abu Shahed,Arif Hasan Khan Robin 한국육종학회 2020 Plant Breeding and Biotechnology Vol.8 No.2

Wheat is globally an important cereal crop. Environmental stress, especially drought stress can play an important rolein the reduction of plant growth, specifically during germination in arid and semi-arid regions. Polyethylene glycol (PEG) treatedhydroponic conditions create negative osmotic potential which is compared with moisture deficit stress. The main objective of thisstudy was to investigate the effects of PEG 6000 induced moderate osmotic stress on germination indices of 22 wheat varieties. In orderto study the effects of osmotic stress on germination indices in wheat cultivars, an experiment was conducted, using a completelyrandomized design with three replications under two different levels of PEG-6000: 0% and 10%. PEG stress significantly reducedpercent germination, shoot length and root length. PEG stress significantly increased root-shoot ratio and oven dry weight. Principalcomponent analysis revealed response of traits of tolerant wheat varieties under osmotic stress. Correlation study revealed thesignificant relationships among germination indices. The variety BARI Gom-30 recorded comparatively higher root length (6 cm),shoot length (7.8 cm), root-shoot ratio (1.37) followed by the variety Sonalika whereas the variety Kalaysona recorded the lowest rootlength (2.7 cm) and shoot length (2.8 cm) under PEG stress. Evolved information of this research including selected traits such asgermination percentage, root-shoot ratio and dry weight of seedlings could be exploited in wheat breeding program for drought andosmotic stress tolerance.