Effect of Gamma Rays on the Growth Performance of Bangladesh Clone Tea

Ali, M. Aslam,Samad, M. A.,Amin, M. K. 한국환경농학회 2005 한국환경농학회지 Vol.24 No.1

The experiment was carried out to investigate the effects of gamma radiation on the early growth performance and physiological traits of BT2 done tea, the most promising cultivar released by Bangladesh Tea Research Institute. The fresh shoot cuttings were irradiated with seven different levels of gamma radiation such as 0, 10,20, 30, 40, 50 and 60 Gy from Cobalt 6OCo source (Dept. of PlantBreeding, Bangladesh Institute of Nudear Agriculture). Thereafter, the irradiated shoot cuttings were planted in polythene bags and kept under natural conditions. It was observed that callusing was initiated from 8th weeks after placement of tea shoot cuttings in the polythene bags and completed by 12th weeks. The morphological growth of tea shoot cuttings were recorded under varying levels of gamma radiation and growth stages. It was observed that the number of leaves, number of primary branches, base diameter, root length and total leaf area per plant significantly increasedwith the progress of time and increasing levels of gamma radiation, however, the plant height showed decreasing trend with the increasing levels of gamma radiation, which could be due to the change in chromosomal structure and genetic makeup. After 56 weeks of planting, the plant height, the number of leaves and primary branches per plant, base diameter, root length and total leaf area per plant recorded were 65.70 cm, 30.67, 7.33, 1.48 cm, 23.50 cm, and 1250.67 cm2 per plant respectively under the radiation level 60 Gy, whereas the corresponding figures of the above parameters at the control treatment were 76.21 cm, 18.33, 3.67, 0.92 cm, 17.75 cm and 778.33 cm2 per plant, respectively. A significant relationship was observed among the physiological growth parameters with the increasing levels of gamma radiation. The total dry matter gain, leaf area index, absolute growth rate and relative growth rate were significantly influenced with the rising levels of gamma radiation (up to 60 Gy), whereas the net assimilation rate of individual tea plant non-significantly responded as compared to those of control treatment. Finally after 56 weeks of planting, the maximum total dry weight gain, leaf area index, absolute growth rate, relative growth rate and net assimilation rate recorded under 60 Gay radiation level were 40.25 g/plant/week, 4.25, 1.18 g/week, 0.0621g/g/week and 17.07 g/m2/week respectively.

Nonlinear mixed models for characterization of growth trajectory of New Zealand rabbits raised in tropical climate

de Sousa, Vanusa Castro,Biagiotti, Daniel,Sarmento, Jose Lindenberg Rocha,Sena, Luciano Silva,Barroso, Priscila Alves,Barjud, Sued Felipe Lacerda,de Sousa Almeida, Marisa Karen,da Silva Santos, Natana Asian Australasian Association of Animal Productio 2022 Animal Bioscience Vol.35 No.5

Objective: The identification of nonlinear mixed models that describe the growth trajectory of New Zealand rabbits was performed based on weight records and carcass measures obtained using ultrasonography. Methods: Phenotypic records of body weight (BW) and loin eye area (LEA) were collected from 66 animals raised in a didactic-productive module of cuniculture located in the southern Piaui state, Brazil. The following nonlinear models were tested considering fixed parameters: Brody, Gompertz, Logistic, Richards, Meloun 1, modified Michaelis-Menten, Santana, and von Bertalanffy. The coefficient of determination (R²), mean squared error, percentage of convergence of each model (%C), mean absolute deviation of residuals, Akaike information criterion (AIC), and Bayesian information criterion (BIC) were used to determine the best model. The model that best described the growth trajectory for each trait was also used under the context of mixed models, considering two parameters that admit biological interpretation (A and k) with random effects. Results: The von Bertalanffy model was the best fitting model for BW according to the highest value of R² (0.98) and lowest values of AIC (6,675.30) and BIC (6,691.90). For LEA, the Logistic model was the most appropriate due to the results of R² (0.52), AIC (783.90), and BIC (798.40) obtained using this model. The absolute growth rates estimated using the von Bertalanffy and Logistic models for BW and LEA were 21.51g/d and 3.16 cm², respectively. The relative growth rates at the inflection point were 0.028 for BW (von Bertalanffy) and 0.014 for LEA (Logistic). Conclusion: The von Bertalanffy and Logistic models with random effect at the asymptotic weight are recommended for analysis of ponderal and carcass growth trajectories in New Zealand rabbits. The inclusion of random effects in the asymptotic weight and maturity rate improves the quality of fit in comparison to fixed models.

Mortality and Early Growth of Q. acuta Seedlings Response to Thinning on Natural Quercus acuta Stands in Wando, Jeonnam Province

여운상,이돈구 한국산림과학회 2004 한국산림과학회지 Vol.93 No.6

For sustainable management of Quercus acuta stands, it is important to know how forest practice affects on natural regeneration of Q. acuta. Thinning is one of the most effective management techniques for forest improvement and successful natural regeneration. This study was carried out to examine the response of mortality and early growth of Q. acuta seedlings in natural Q. acuta stands in Wando, Jeonnam Province. Mortality of Q. acuta seedlings showed different patterns between natural unthinned Q. acuta and thinned Q. acuta stands. In the thinned stand, mortality of seedlings differed significantly among different height and diameter classes, higher mortality was shown at lower height and root collar diameter classes. However, similar mortality was observed in unthinned Q. acuta stand in all classes. Mean height and root collar diameter of total Q. acuta seedlings increased for three to four years after thinning and then slightly decreased in 2003 and 2004. But, advance regeneration continuously increased and upper 10% height class rapidly increased. In unthinned stand, higher absolute growth rate(AGR) and relative growth rate(RGR) of root collar diameter and height were shown at lower height and root collar diameter classes. On the other hand, AGR increased with tree size and RGR was relatively constant among trees of different classes except the lowest class in thinned stand.

Heat stress effects on the genetics of growth traits in Thai native chickens (Pradu Hang dum)

Wuttigrai Boonkum,Vibuntita Chankitisakul,Srinuan Kananit,Wootichai Kenchaiwong Asian Australasian Association of Animal Productio 2024 Animal Bioscience Vol.37 No.1

Objective: The objective of this study was to investigate the effect of heat stress on the growth traits and genetic parameters of Thai native chickens. Methods: A total of 16,487 records for growth traits of Thai native chickens between 2017 and 2022 were used in this study. Data included the body weight at birth, body weight at 4, 8, and 12 weeks of age (BW0, BW4, BW8, BW12), average daily gain during 0 to 4, 4 to 8, and 8 to 12 weeks of age (ADG0-4, ADG4-8, ADG8-12), absolute growth rate at birth, at 4, 8, and 12 weeks of age (AGR0, AGR4, AGR8, AGR12). The repeatability test day model used the reaction-norm procedure to analyze the threshold point of heat stress, rate of decline of growth traits, and genetic parameters. Results: At temperature and humidity index (THI) of 76, Thai native chickens began to lose their growth traits, which was the onset of heat stress in this study. The estimated heritability, genetic correlation between animal and heat stress effect, and correlations between the intercept and slope of the permanent environmental effects were 0.27, -0.85, and -0.83 for BW, 0.17, -0.81, and -0.95 for ADG, 0.25, -0.61, and -0.83 for AGR, respectively. Male chickens are more affected by heat stress than female chickens with a greater reduction of BW, ADG, and AGR, values equal to -9.30, -0.23, -15.21 (in males) and -6.04, -0.21, -10.10 (in females) gram per 1 level increase of THI from the THI of 76. Conclusion: The influence of thermal stress had a strong effect on the decline in growth traits and genetic parameters in Thai native chickens. This study indicated that genetic models used in conjunction with THI data are an effective method for the analysis and assessment of the effects of heat stress on the growth traits and genetics of native chickens.

Mortality and Early Growth of Q. acuta Seedlings Response to Thinning on Natural Quercus acuta Stands in Wando, Jeonnam Province

( Un Sang Yeo ),( Don Koo Lee ) 한국산림과학회 2004 한국산림과학회지 Vol.93 No.6

N/A For sustainable management of Quercus acuta stands, it is important to know how forest practice affects on natural regeneration of Q. acuta. Thinning is one of the most effective management techniques for forest improvement and successful natural regeneration. This study was carried out to examine the response of mortality and early growth of Q. acuta seedlings in natural Q. acuta stands in Wando, Jeonnam Province. Mortality of Q. acuta seedlings showed different patterns between natural unthinned Q. acuta and thinned Q. acuta stands. In the thinned stand, mortality of seedlings differed significantly among different height and diameter classes, higher mortality was shown at lower height and root collar diameter classes. However, similar mortality was observed in unthinned Q. acuta stand in all classes. Mean height and root collar diameter of total Q. acuta seedlings increased for three to four years after thinning and then slightly decreased in 2003 and 2004. But, advance regeneration continuously increased and upper 10% height class rapidly increased. In unthinned stand, higher absolute growth rate(AGR) and relative growth rate(RGR) of root collar diameter and height were shown at lower height and root collar diameter classes. On the other hand, AGR increased with tree size and RGR was relatively constant among trees of different classes except the lowest class in thinned stand.

Effects of Carbohydrate Availability on Growth and Flowering in Chrysanthemum under Different Photoperiods

Byung-Joo Lee,Mi-Kyoung Won,Euy-Seog Yang,Jong Suk Lee,Jeffrey Gordon Atherton 한국원예학회 2004 Horticulture, Environment, and Biotechnology Vol.45 No.6

Carbohydrate production and partitioning were examined under different photoperiods in chrysanthemum (Dendranthema grandiflorum cv. Envy). Sucrose was the principal sugar at the shoot tips of chrysanthemum analyzed under inductive 10 h photoperiods. Fructose and glucose were only present in smaller quantities compared to sucrose. Sucrose content at the shoot tip increased more than 1.5-fold within a day in 10 and 13 h short photoperiods and remained static for 9 days compared to vegetative plants in 16 h photoperiods. Growth parameters such as total dry weight, leaf area, absolute growth rate, and final leaf number increased as photoperiods extended from 10 to 16 h, whereas floral development and partitioning of carbohydrate to floral parts measured by flower weight ratio were highest under 10 h photoperiods. Net assimilation rate was highest at 10 h photoperiods followed by 16 and 13 h photoperiods, indicating higher productivity of source leaves at 10 h photoperiods than of 13 or 16 h photoperiods.

DQI와 단기 상대생장률 분석을 이용한 원통형 종이포트 토마토 접목묘의 우량묘 기준 설정

서태철(Tae Cheol Seo),안세웅(Se Woong An),장현우(Hyun Woo Jang),남춘우(Chun Woo Nam),전희(Hee Chun),김영철(Young chul Kim),강태경(Tae Kyung Kang),이상희(Sang Hee Lee) (사)한국생물환경조절학회 2018 생물환경조절학회지 Vol.27 No.4

3종의 일반토마토 ‘대프니스’, ‘도태랑다이아’, ‘마스카라’를 대목 ‘B블로킹’에 접목하고 접목 활착 후 10일부터 10일 간격으로 40일 까지 육묘용 표준양액(S)의 0.5S, 1,0S, 2,0S 로 시비수준 처리를 하였다. 각 시기별로 묘의 생육인자들을 조사하였고, 묘소질 지표인 TR율, 충실도, DQI를 계산하였다. 그리고 생육인자들과 묘소질 지표와의 상관관계를 분석하였고, 묘령별로 야간온도를 10, 15, 25℃를 목표로 3수준으로 처리하여 상대생장률(RGR)을 분석하였다. 그 결과, 토마토 접목묘의 양적인 생육인자들은 모두 시비농도가 높을수록 증가하였고, 다양한 크기 범위의 묘를 생산할 수 있었다. 그리고 묘의 바이오메스 관련 생육인자가 충실도와 DQI에 높은 정의상관이 있음을 알 수 있었으며, 충실도와 DQI의 고도로 유의한 1차 선형회귀식((Y=-0.0256+0.0029*X, Adj R<SUP>2</SUP>=0.9480, p<0.0001)이 도출되었다. 정식 후 2주간의 RGR은 묘령이 높아질수록 감소하는 경향을 보였고, 육묘기 시비수준에 따라서는 접목활착 후 30일묘와 40일묘에서 표준 시비수준 1.0S에서 RGR이 높았다. 시비수준별 육묘기 DQI와 정식후 초기 RGR과 유의한 선형회귀식을 도출하였으며, 표준 시비수준 1.0S에서 DQI가 높아짐에 따라 RGR이 높게 유지되었다. 이러한 결과는 DQI가 원통형 종이포트 토마토 접목묘의 묘소질의 지표로 이용될 수 있고, DQI와 정식 후 초기 상대생장률과의 관계분석을 통하여 우량묘의 기준 설정에 활용될 수 있을 것이다. Using cylindrical paper pot nursery method, three kinds of commercial tomatoes ‘Dafnis’, ‘DOTAERANG DIA’ and ‘Maescala’ were grafted onto a commercial rootstock ‘B blocking’. From 10 to 40 days after graft-take, growth traits of seedlings were investigated by 0.5, 1.0 and 2.0S treatments of standard nutrient solution(S) for seedling growth, and top to root ratio(TRR), compactness(CP) and Dickson Quality Index(DQI) were calculated. Two weeks after transplanting of the seedlings under three different night temperature targeting to 10, 15, and 25℃, which were not precisely controlled, the relative growth rate (RGR) was investigated. The quantitative growth traits of grafted seedlings increased with increasing fertilizer concentration, and various range of seedling size could be produced. Compactness and DQI were significantly regressed (Adj R<SUP>2</SUP> = 0.9480). Short-term RGR after transplanting was higher at 1.0S treatment of standard nutrient solution at the seedling age of 30 days and 40 days after grafttake( DAGT). DQI and RGR were significantly regressed linearly at respective fertigation strength. Specially the diminishing slope of RGR was lower at 1.0S fertigation strength with the increase of DQI than others. The results indicate that DQI could be applied as a quality index of grafted tomato seedlings and the relation analysis between DQI and short-term RGR also could be used to determine the good quality seedlings of grafted tomato grown in cylindrical paper pot.

Different Activities of Pectin-degrading Enzymes Affecting the Growth of Asian Pears

Yun-Ju Baek,Sang Wook Park,Bok-Rye Lee,Ung Yang,Sol Han,Seung Gon Wi,Sang-Hyun Lee 한국원예학회 2023 원예과학기술지 Vol.41 No.5

단일과 장일 조건에서의 광량이 국화의 생육과 개화에 미치는 영향

이병주,Jeffrey G. Atherton 한국화훼산업육성협회 2004 화훼연구 Vol.12 No.4