Effect of grafting on growth and incidence of phytophthora blight and bacterial wilt of pepper (Capsicum annuum L.)

This study was conducted to investigate the effect of grafting using commercial rootstocks and breeding lines on growth and resistance to both Phytophthora blight (Phytophthora capsici) and bacterial wilt (Ralstonia solanacearum), and to evaluate the breeding lines as candidates rootstocks for grafted peppers. Capsicum annuum 'Nokkwang' (scion) was grafted onto five commercial rootstocks ('Kataguruma', 'Konesianhot', 'Koregon PR-380', 'PR-power', and 'Tantan') and nine breeding lines ('PR 901', 'PR 919', 'PR 920', 'PR 921', 'PR 922', 'PR 927', 'PR 928', 'PR 929', and 'PR 930'). Graft-take percentage was over 80% in all the grafted seedlings except those grafted onto 'PR 901' (75%). The number of leaves, stem diameter, leaf area, and dry weight of shoot of grafted seedlings were greater than those of non-grafted seedlings. Mineral contents in the shoots of grafted seedlings were significantly different, depending on rootstock genotypes. Marketable yield ranged from 1.35 to 1.96 kg per plant depending on rootstock genotypes, and was highest in peppers grafted onto 'PR 901' (1.95 kg) and non-grafted peppers (1.96 kg), and lowest in those grafted onto 'PR 928' (1.35 kg). Gross yield was highest in peppers grafted onto 'Konesianhot' (2.64 kg). Among nine breeding lines, three rootstocks ('PR 920', 'PR 921', and 'PR 922') were selected as candidate rootstocks for the grafted pepper based on graft-take, growth, yield, fruit quality, and resistance to diseases. Three major pepper cultivars ('Nokkwang', 'Saengsaeng Matkkwari', and 'Shinhong') were grafted onto those three breeding lines and 'Tantan' (control). Peppers grafted onto breeding lines of 'PR 920', 'PR 921', and 'PR 922' showed greater resistance to both Phytophthora blight and bacterial wilt without the decrease in yield and fruit quality. Accordingly, they were considered to be used as rootstocks resistant to both Phytophthora blight and bacterial wilt for pepper production.OAIID:oai:osos.snu.ac.kr:snu2012-01/102/0000027607/1SEQ:1PERF_CD:SNU2012-01EVAL_ITEM_CD:102USER_ID:0000027607ADJUST_YN:YEMP_ID:A075898DEPT_CD:517CITE_RATE:0FILENAME:2012-2-heb-접목-내병성-장윤아.pdfDEPT_NM:식물생산과학부EMAIL:[email protected]_YN:NCONFIRM:

Effects of Light Quality and Intensity on the Carbon Dioxide Exchange Rate, Growth, and Morphogenesis of Grafted Pepper Transplants during Healing and Acclimatization

This study evaluated the influence of light quality and intensity during healing and acclimatization on the CO2 exchange rate, growth, and morphogenesis of grafted pepper (Capsicum annuum L.) transplants, using a system for the continuous measurement of the CO2 exchange rate. C. annuum L. 'Nokkwang' and 'Tantan' were used as scions and rootstocks, respectively. Before grafting, the transplants were grown for four weeks in a growth chamber with artificial light, where the temperature was set at 25/18 degrees C #light/dark period# and the light period was 14 hours.d#-1#. The grafted pepper transplants were then healed and acclimatized under different light quality conditions using fluorescent lamps #control# and red, blue, and red + blue light-emitting diodes #LEDs#. All the transplants were irradiated for 12 hours per day, for six days, at a photosynthetic photon flux #PPF# of 50, 100, or 180 mu mol.m#-2#.s#-1#. The higher PPF levels increased the CO2 exchange rate during the healing and acclimatization. A smaller increase in the CO2 exchange rates was observed in the transplants under red LEDs. At a PPF of 180 mu mol.m#-2#.s#-1#, the CO2 exchange rate of the transplants irradiated with red LEDs was lowest and it was 37% lower than those irradiated with fluorescent lamps. The CO2 exchange rates of transplants irradiated with blue LEDs was the highest and 20% higher than those irradiated under fluorescent lamps. The graft take was not affected by the light quality. The grafted pepper transplants irradiated with red LEDs had a lower SPAD value, leaf dry weight, and dry matter content. The transplants irradiated with blue LEDs had longer shoot length and heavier stem fresh weight than those irradiated with the other treatments. Leaves irradiated with the red LED had the smallest leaf area and showed leaf epinasty. In addition, the palisade and spongy cells of the pepper leaves were dysplastic and exhibited hyperplasia. Grafted pepper transplants treated with red + blue LEDs showed similar growth and morphology to those transplants irradiated with fluorescent lamps. These results suggest that high-quality grafted pepper transplants can be obtained by healing and acclimatization under a combination of blue and red lights at a high PPF level.OAIID:oai:osos.snu.ac.kr:snu2013-01/102/0000027607/2SEQ:2PERF_CD:SNU2013-01EVAL_ITEM_CD:102USER_ID:0000027607ADJUST_YN:YEMP_ID:A075898DEPT_CD:517CITE_RATE:.237FILENAME:2013-2-kjhst-고추접목묘-활착중광질광도_광합성-장윤아.pdfDEPT_NM:식물생산과학부EMAIL:[email protected]_YN:NCONFIRM:

Effect of Low-Temperature Tolerant Rootstocks on the Growth and Fruit Quality of Watermelon in Semi-Forcing and Retarding Culture

Watermelon grafting is practiced in order to improve tolerance to poor environments such as low temperature. This study was conducted to investigate the effect of low-temperature tolerant bottle gourd (Lagenaria siceraria) rootstocks on the growth and fruit quality of watermelon in semi-forcing and retarding culture where plants were exposed to low or high temperature. Five bottle gourd accessions (FR79, IT207112, BG702, BG703, and FRD22) with low temperature tolerance were evaluated as rootstock for the watermelon scion ‘Sambokkul’. Non-grafted watermelon and watermelon grafted onto commercial rootstock ‘Shintozwa’ (Cucurbita maxima D. × C. moschata D.) or ‘Bullojangsaeng’ (L. siceraria) were used as controls. Watermelons were cultivated in spring (April to June, semi-forcing culture) and autumn (August to October, retarding culture). The responses to low-temperature, growth, yield, and fruit quality differed depending on the rootstocks and growing season. In semi-forcing culture, the monthly averages of daily and minimum temperature in April were, respectively, 13.4 and 1.5 °C. Although the low temperature of the early growth stage suppressed the initial growth of watermelons, grafting mitigated the low-temperature stress. The fruit quality of non-grafted watermelons was greater, but the fruit mass was the lowest (4.8 kg). Grafting onto ‘Shintozwa’ increased the fruit weight (7.0 kg) but reduced the fruit quality. Grafting onto bottle gourd rootstocks had high affinity, good root growth, tolerance to low temperature, and little effect on fruit quality. In retarding culture, the temperature conditions in early and late growth were very high and low, respectively. The growth and fruit quality of grafted watermelons were not superior to those of non-grafted watermelons. Accordingly, these results suggest that watermelon grafting onto the bottle gourd rootstocks may increase the low-temperature tolerance, especially in the early growth stage, and the marketable yield without a reduction in fruit quality. The most promising accession for this purpose was found to be ‘FR79’

A Preliminary Study for Identifying Quantitative Trait Loci Associated with Seed Production in Radish Using Genotyping-by-Sequencing

The high yield of seeds can reduce the cost of seed production for parental lines, as well as F1 cultivars in radish. The number of seeds per silique and silique length are two important traits among traits determining seed yield, but no study has been conducted on their quantitative trait loci (QTLs) in radish. A high-density linkage map was constructed, based on genotyping-by-sequencing (GBS) of the F2 population, derived from two parental lines, significantly differed by the two traits, which were grown in a controlled environment to minimize the environmental effects. Using the map with 848 SNPs, three significant QTLs were identified, two and one of which were associated with the number of seeds per silique and silique length, respectively. Ortholog analysis was conducted with Arabidopsis thaliana genes, related to the number of seeds per silique, and revealed five radish putative candidate genes. These putative candidate genes appear to be related to ovule, embryo sac, embryo, pollen and seed development, as well as a double fertilization process. The method to pollinate the F2 population, as well as preliminary QTLs and SNPs therein, can be helpful for future QTL studies to improve seed production in radish breeding programs

A Preliminary Study for Identifying Quantitative Trait Loci Associated with Seed Production in Radish Using Genotyping-by-Sequencing

The high yield of seeds can reduce the cost of seed production for parental lines, as well as F1 cultivars in radish. The number of seeds per silique and silique length are two important traits among traits determining seed yield, but no study has been conducted on their quantitative trait loci (QTLs) in radish. A high-density linkage map was constructed, based on genotyping-by-sequencing (GBS) of the F2 population, derived from two parental lines, significantly differed by the two traits, which were grown in a controlled environment to minimize the environmental effects. Using the map with 848 SNPs, three significant QTLs were identified, two and one of which were associated with the number of seeds per silique and silique length, respectively. Ortholog analysis was conducted with Arabidopsis thaliana genes, related to the number of seeds per silique, and revealed five radish putative candidate genes. These putative candidate genes appear to be related to ovule, embryo sac, embryo, pollen and seed development, as well as a double fertilization process. The method to pollinate the F2 population, as well as preliminary QTLs and SNPs therein, can be helpful for future QTL studies to improve seed production in radish breeding programs

Drought Tolerance Evaluation and Growth Response of Chinese Cabbage Seedlings to Water Deficit Treatment

Drought is a significant climatic factor that significantly affects the production of Chinese cabbage, a crop that is highly susceptible to drought stress. The development and cultivation of drought-tolerant varieties could be a viable strategy to minimize the damage caused by climate change and ensure stable production of Chinese cabbage. This requires the implementation of technologies for early evaluation and selection of a plethora of resources. In this study, we screened 100 varieties and breeding resources for drought tolerance under a water deficit treatment at the seedling stage. We also evaluated the growth response of Chinese cabbage varieties and breeding resources under water deficit treatment and selected drought-tolerant Chinese cabbage genotypes. We confirmed that the visual score for wilting, which evaluates the wilting response during the recovery process of Chinese cabbage seedlings through water deficit treatment and re-watering, can be used as an indicator for evaluating tolerance to drought stress. The visual score for wilting showed a high correlation with major traits representing drought tolerance. Our findings highlight the need for an integrated approach that considers various environmental conditions, varieties, and lines to select and develop drought-tolerant varieties. We selected ‘18-FH112-1’ and ‘18-FH112-1-2’ among others, and these germplasms will be useful resources for drought tolerance breeding. This study provides a foundation for future efforts to develop drought-tolerant Chinese cabbage varieties, thereby contributing to the stable production of this crucial crop

Effect of Low-Temperature Tolerant Rootstocks on the Growth and Fruit Quality of Watermelon in Semi-Forcing and Retarding Culture

Watermelon grafting is practiced in order to improve tolerance to poor environments such as low temperature. This study was conducted to investigate the effect of low-temperature tolerant bottle gourd (Lagenaria siceraria) rootstocks on the growth and fruit quality of watermelon in semi-forcing and retarding culture where plants were exposed to low or high temperature. Five bottle gourd accessions (FR79, IT207112, BG702, BG703, and FRD22) with low temperature tolerance were evaluated as rootstock for the watermelon scion ‘Sambokkul’. Non-grafted watermelon and watermelon grafted onto commercial rootstock ‘Shintozwa’ (Cucurbita maxima D. × C. moschata D.) or ‘Bullojangsaeng’ (L. siceraria) were used as controls. Watermelons were cultivated in spring (April to June, semi-forcing culture) and autumn (August to October, retarding culture). The responses to low-temperature, growth, yield, and fruit quality differed depending on the rootstocks and growing season. In semi-forcing culture, the monthly averages of daily and minimum temperature in April were, respectively, 13.4 and 1.5 °C. Although the low temperature of the early growth stage suppressed the initial growth of watermelons, grafting mitigated the low-temperature stress. The fruit quality of non-grafted watermelons was greater, but the fruit mass was the lowest (4.8 kg). Grafting onto ‘Shintozwa’ increased the fruit weight (7.0 kg) but reduced the fruit quality. Grafting onto bottle gourd rootstocks had high affinity, good root growth, tolerance to low temperature, and little effect on fruit quality. In retarding culture, the temperature conditions in early and late growth were very high and low, respectively. The growth and fruit quality of grafted watermelons were not superior to those of non-grafted watermelons. Accordingly, these results suggest that watermelon grafting onto the bottle gourd rootstocks may increase the low-temperature tolerance, especially in the early growth stage, and the marketable yield without a reduction in fruit quality. The most promising accession for this purpose was found to be ‘FR79’

Evaluation of Air Temperature, Photoperiod and Light Intensity Conditions to Produce Cucumber Scions and Rootstocks in a Plant Factory with Artificial Lighting

Air temperature and light conditions are important factors not only to produce high-quality seedlings but also to promote energy efficiency in a plant factory with artificial lighting. In this study, we conducted two experiments in order to investigate the favorable conditions of air temperature, light intensity and photoperiod for the production of cucumber scions and rootstocks in a plant factory with artificial lighting. Cucumber scions and rootstocks were cultivated in two combined treatments: the combination of three different levels of difference between the day and night temperature (DIF), 25/20, 26/18 and 27/16 °C and five different light intensity conditions of photosynthetic photon flux, 50, 100, 150, 200 and 250 μmol·m−2·s−1 was set for the first experiment, and the combination of three different photoperiod conditions, 12, 16 and 20 h·d−1 and five different light intensity conditions, 50, 100, 150, 200 and 250 μmol·m−2·s−1 was set for the second experiment. In the air temperature and light intensity treatments, the hypocotyl elongation of cucumber scions and rootstocks was affected more largely by light intensity than DIF. The highest DIF treatment (27/16 °C) affected negatively on the accumulation of dry mass. On the contrary, the smallest DIF treatment (25/20 °C) was favorable for seedling growth due to lesser stress by rapid change of air temperature between photo- and dark-period. In the photoperiod and light intensity treatments, an increased DLI (daily light integral) promoted the growth of scions and rootstocks. Under the same DLI condition, the growth of scions and rootstocks increased with increasing photoperiod and decreasing light intensity. In both of experiments, while the dry weight increased with increasing the light intensity, the light use efficiencies were reduced by increasing the light intensity. Considering the growth and quality of seedlings and energy efficiency, the optimal environment conditions were represented by 25/20 °C of air temperature, 150 μmol·m−2·s−1 of light intensity and 16 h·d−1 of photoperiod