• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.36 no.2
• /
• pp.134-142
• /
• 1991

Since IR8, the first high-yielding rice cultivar characterised by semidwarf and high-tillering, was released in 1966, rice yields during the last two decades have apparently reached a plateau and subsequent efforts to further improve yielding ability have not resulted in visible gains. At this point of time, a new ideotype of rice plant would be necessary to increase grain yield potential. This experiment was conducted to investigate the yield contribution of different tillers within a plant in relation to an ideo type of rice plant. A low-tillering, large panicled IR25588 was compared with a high-tillering, small panicled IR58. Based on spikelet number and grain weight per panicle, the top six panicles in both low- and high-tillering cultivarswere significantly bigger than those in the other panicles. The top six panicles were M, PI, P2, P3, P4 and S1P2 in both cultivars. Their tillers had 100% probability of occurring. The top six tillers were characterised by earlier initiation and heading, longer growth duration, greater leaf area. and heavier culm and total dry weight per tiller. The top six panicles, based on grain weight was mainly due to higher spikelet number per panicle with little differences in 1,000 grain weight and percent fertility. They had also a greater number of high -density grains. The top six panicles were significantly bigger than the rest of the panicles in both low- and high-tilliering types suggesting that a new rice ideotype having six or fewer potential tillers or panicles per paint with 200 to 250 spikelets per panicle (a low-tillering, paicle weight type) may help increase grain yield potential since they have been shown to be superior physio-morphologically to the rest of the tillers.

• Journal of Bio-Environment Control
• /
• v.20 no.1
• /
• pp.27-32
• /
• 2011

This study was carried out to investigate characteristics of new garlic cultivar 'Alkae' and to identify the effect of scape removal on bulb characteristics and growth of garlic cultivar 'Alkae' and 'Namdo'. Bolting time and harvesting time were earlier about 20 days in 'Alkae' than those in 'Namdo'. 'Alkae' was inferior to 'Namdo' in top growth as plant height, number of leaves, leaf area, SPAD value, diameter of leaf sheath, and so on. but root developing was better in 'Alkae'. Bulb weight of' Alkae' was 17% more than that of 'Namdo', harvested on proper time. The ratio of bulb weight over 40 g was almost double in 'Namdo' as 48% with 'Alkae' as 25%. Occurrence of bulb cracking was more considerable in 'Alkae' and the number of clove per bulb was 1.9 more in 'Alkae' than 'Namdo', but the ratio of bulb rot during storage was higher in 'Namdo' than 'Alkae'. In treatments of scape removal, SPAD value did not show any difference between two cultivars. Leaf dryness was earlier and harder than control and leaf area showed the same tendency as leaf dryness, and there were no significant differences among the methods of scape removal. The bulb weight and the ratio of bulb weight over 40 g at 50 days after the harvest of 'Alkae', 'Namdo' were more 10%, 12% and 27%, 44% in scape removal treatment than control. and there were no significant differences among the methods of scape removal. So, scape removal was very effective to increase large bulb production in the two garlic cultivals and the effect was higher in 'Namdo' than 'Alkae'. The ratio of bulb cracking and the occurrence of bulb rot were almost same in with the scape removal and non removal groups And also there were no significant differences among the methods of scape removal.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.57 no.3
• /
• pp.248-253
• /
• 2012

Demand is increasing for new functional and health food such as natually colored or flavored rices. Shinongheugchal, Shinmyeongheugchal, colored glutinous rice, were breed as new variety in Jeollabuk-do ARES. Shinongheugchal and Shinmyeongheugchal are medium to late maturing cultivars and higher than Heugnambyeo in term of C3G content. It was conducted to improve the quality of Shinongheugchal, Shinmyeongheugchal in different cultivation regions, transplanting time. The cultivation regions was Jinan (mid-mountainous area) and Iksan (plain area). Transplanting time was May. 20, May. 25 May 30 and Jun. 5 in Jinan, that of Iksan was Jun. 5, Jun. 10, Jun. 15 and Jun. 20. The average heading date of Shinongheugchal and Shinmyeongheugchal was Aug. 13, Aug. 19 and Aug. 15, Aug. 22 in Jinan and Iksan. The average yield of Shinongheugchal(brown rice) in Jinan was 514 $kg\;10a^{-1}$ and that of in Iksan was 529 $kg\;10a^{-1}$. The average yield of Shinmyeongheugchal(brown rice) in Jinan was 508 $kg\;10a^{-1}$ and that of in Iksan was 511 $kg\;10a^{-1}$. The average C3G content of Shinongheugchal in Jinan was 273.9 mg/100g, that of in Iksan was 228.2 mg/100g. The average C3G content of Shinmyeongheugchal in Jinan was 126.3 mg/100g, that of in Iksan was 101 mg/100g. The optimal transplanting date was May 30 in Jinan and June 10 in Iksan considering the yield and C3G content in Shinongheugchal. The optimal harvesting date of Shinongheugchal in Iksan was 50 days after heading.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.64 no.4
• /
• pp.299-310
• /
• 2019

The eating quality of rice is one of the main concerns of rice breeding programs in many countries, especially in japonica rice cultivation areas. To select new resources with high eating quality from Korean native japonica rice, we evaluated a total of 76 varieties, including 47 native rice resources (26 landraces + 21 weedy rice) of Korea. In this study, all eating quality traits varied widely among the native resources, and some of the native resources revealed a high evaluation score in the palatability, expected eating quality, and physicochemical traits among the tested whole-plant materials. From the results, we selected two landraces (Sangdo and Waebyeo) and three weedy rice varieties (Hoengseongaengmi3, Namjejuaengmi6, and Wandoaengmi6) as promising resources for improvement of rice eating quality. Specifically, Wandoaengmi6 presented potential as a key breeding material for improving the eating quality of Korean rice cultivars, having the best evaluation results in palatability score (PS 0.83) from the sensory test and glossiness value (GV 81.8) from the Toyo taste meter of cooked rice. Given the urgent need to overcome the constraint of the narrow genetic background of Korean japonica rice, the results could be a practical solution for exploring new opportunities for improving rice eating quality through the expansion of genetic resources.

• Journal of Life Science
• /
• v.22 no.7
• /
• pp.871-879
• /
• 2012

Polyploids are a potentially important germplasm source in seedless citrus breeding program. Seedlessness is one of the most promising traits of commercial mandarin breeds that mandarin triploid hybrids possess permanently. The formation of new constant triploid hybrids can be recovered through diploid species hybridization from the fusion of divalent gametes at low frequencyor intra-and inter-ploidy crosses. However, extensive breeding work based on small $F_1$ hybrid seeds developed is impossible without a very effective aseptic methodology and ploidy event. In this study, in vitro embryo culture was employed to recover natural hybrids from monoembryonic diploid, open-pollinated mandarin. Flow cytometry was used to determine ploidy level. A total of 10,289 seeds were extracted from 792 fruits having approximately 13 seeds per fruit. Average frequency of small seeds developed was 7.1%, while the average frequency of small seeds per fruit were: 8.9% for 'Clementine' 10.2% for 'Harehime' 2.6% for 'Kamja' 3.1% for 'Pyunkyool' 2.8% for 'Sadookam' and 7.0% for 'Wilking' mandarin. Average size of a perfect seed was $49.52{\pm}0.07mm^2$ ('Clementine') while the small seed measured $7.95{\pm}0.04mm^2$ ('Clementine'), which was about 1/6 smaller than the perfect seed. In total, 731 small seeds were obtained and all of them contained only one embryo per seed. The efficiency of 'Clementine' was 14 times higher than 'Wilking' and more than 109 times higher than 'Pyunkyool'. The basic information on spontaneous polyploidy provides for the hybridization of constant triploids and increases the efficiency of conventional cross.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.60 no.3
• /
• pp.318-332
• /
• 2015

The maize production in South-eastern Asian countries showed a continuous increase with increasing poultry-livestock from the beginning of the 1990s to early 2010. Also the need for a new variety development of each contries was increased rapidly in the same period. Single-Cross hybrid varieties have been developed and supplied from 2001 instead of multi-cross maize varieties since 1992 in Indonesia. In Cambodia, CP group is mainly manufacturing feeds with most of the forage maize from farmers who are growing its seeds from the company. Cambodian main cultivars are varieties of multinational corporations such as DK8868 from Monsanto, NK6326, NK7328 from Syngenta and CP333 from CP group including local business company. Vietnam is the main maze importing country in South-Eastern Asia which had imported 13 times scale of amount compared to exports in average from 1990 to 2011. Vietnamese government has developed a range of varieties for improving their efficiency in production, such as the LVN-10 with political investments. Their production has been reached to 80% of the total. According to the 2012 MIFAFF (Ministry for Food, Agriculture, Forestry and Fisheries) data in Korea, domestic edible maize cultivation area was approximately 15,000ha. It showed 74,399 tons of production, 3.8% of food self-sufficiency in maize and around 0.9% of grain self-sufficiency rate. The consumption of grain is mostly rely on imports in Korea. To overcome the limit of the domestic seed market and increase maize self-sufficiency, the need to develop maze varieties for world-class is increasing at present through analyzing the market trend and prospect of the seed industry in South-eastern Asia.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.65 no.3
• /
• pp.214-221
• /
• 2020

Salinity is one of the major abiotic stressors that inhibits the growth, yield, and productivity of crop plants. Therefore, it is necessary to develop crops with increased salt tolerance for cultivation in saline soils such as is found in reclaimed land. The objective of this study was to develop a salt-tolerant silage rice line that grows on reclaimed land. In order to develop this salt-tolerant silage rice, we transferred Saltol, a major QTL associated with salt tolerance, from IR64-Saltol, a salt-tolerant indica variety, into Mogyang, a susceptible elite japonica variety. To determine the effect of salt stress, Mogyang and IR64-Saltol cultivars were grown on a medium containing various concentrations of NaCl in in vitro conditions. Shoot length was found to decrease with increasing salt concentrations, and root growth was almost arrested at NaCl concentrations over 50 mM in the Mogyang cultivar. Based on these preliminary results, we screened five salt-tolerant lines showing superior growth under salt stress conditions. Polymerase chain reaction and sequencing results showed that the introgression types of Saltol QTL were derived from the IR64-Saltol cultivar in almost all selected lines. Based on the observed growth and physiological characteristics, the new Saltol introgression lines showed higher salt tolerance compared to the Mogyang parental cultivar. The salt-tolerant lines identified in this study could be used as a genetic resource to improve rice salt tolerance.

• Horticultural Science & Technology
• /
• v.29 no.5
• /
• pp.474-481
• /
• 2011

Potato late blight caused by the fungus Phytophthora infestans is one of the most vital diseases damaging the potato plant. It is for this reason that breeding potato cultivars resistant to late blight is now becoming a major concern around the world. The B3C1 clones has been introduced by the Highland Agriculture Research Center, RDA. The clones which came from International Potato Center in 2005 have a durable resistance to late blight. The clones were bred under a short-day condition in Peru. However, there was still no report on the adaptability of these clones to the long-day condition in Korea. Therefore, this study was conducted to evaluate the late blight resistance and major agronomic characteristics of B3C1 clones under Korea's long-day condition. This study was also done to generate genetic resources for developing new varieties resistant to late blight. In this study it was found out that in naturally infested field with P. infestans, AUDPC (area under disease progress curve) values of all B3C1 clones were significantly lower than those of the control varieties, 'Superior', 'Atlantic', and 'Haryeong'. It was found out that B3C1 clones had a high level of resistance to late blight and that they could be used as genetic resources to breed potato varieties with late blight resistance. However, several undesirable characteristics such as extremely late maturity, excessive growth of stems and stolons, and production of tubers that cannot easily be removed from the stolons were also observed. Among the twenty B3C1 clones, two clones, LB-8 (CIP393077.159) and LB-11 (CIP393371.159), were selected for cultivating at the highland area of Korea. Two B3C1 clones were crossed with Korean breeding lines and clonal selection for the progenies is still in progress.

• Horticultural Science & Technology
• /
• v.30 no.6
• /
• pp.780-783
• /
• 2012

A new strawberry cultivar (Fragaria ${\times}$ ananassa Duch.) 'Okmae' was developed from a cross between 'Toyonoka' and 'Maehyang'. This cultivar has a good fruit quality and suitable number of flowers per cluster for labor saving in fruit thinning. 'Gyoengnam No. 1' was selected as an elite line with vigorous plant growth, higher soluble solids content and fruit firmness after examining its characteristics and productivity in forcing cultures from 2007 to 2009. Farmer's field trial of 'Gyoengnam No. 1' was conducted in 2010 and it was registered as 'Okmae' thereafter. The general characteristics of 'Okmae' are vigorous growth habit, erect plant type, less number of leaf and elliptic leaf shape. 'Okmae' has long peduncle and 9-10 flowers per flower cluster which need less labor for fruit thinning. Fruits of 'Okmae' are conical having a bright red and glossy skin color. Although 'Okmae' has a smaller average fruit number per plant of 21.9 than that of the control cultivars, it's possible to produce high yield because of greater fruit weight of 26.0 g. 'Okmae' showed a high soluble solids content of $11.6^{\circ}Brix$, low acidity of 0.37%, and high firmness of $14.5g{\cdot}mm^{-2}$. It is sensitive to anthracnose and powery mildews, but high-quality strawberry can be harvested by using effective control measure.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.45 no.7
• /
• pp.980-989
• /
• 2016

In the present study, we compared and investigated the nutritional compositions of Amaranthus cruentus and Amaranthus hypochondriacus baby-leaves cultivated in Korea. Baby-leaves of two amaranthes consisted of more than 92% moisture, and A. cruentus contained a higher amount of moisture than A. hypochondriacus. Meanwhile, A. hypochondriacus contained higher levels of crude ash, crude protein, crude lipid, carbohydrates, and dietary fiber than A. cruentus. The major free sugars of the two amaranth baby-leaves were fructose and glucose. Fructose content of A. hypochondriacus was higher than that of A. cruentus, and glucose content of A. cruentus was higher than that of A. hypochondriacus. Acetic acid, malic acid, and fumaric acid were detected in two amaranth leaves, but succinic acid was not detected. Two amaranth leaves contained 17 amino acids except for methionine, proline, and tyrosine, and leaves contained the highest glutamic acid contents. In addition, A. cruentus and A. hypochondriacus leaves contained high contents of taurine and ${\gamma}$-aminobutyric acid and showed various biological activities. The major mineral and fatty acid of the two amaranth leaves were potassium and linolenic acid (C18:3), respectively. The ${\beta}$-carotene contents of A. cruentus and A. hypochondriacus leaves were $478.72{\mu}g/100g$ and $474.12{\mu}g/100g$, respectively. In vitamin B complex, $B_2$, $B_3$, and $B_5$ were detected in the two amaranth leaves whereas vitamins $B_1$, $B_6$, and $B_{12}$ were not detected. A. hypochondriacus contained higher amounts of vitamin C and E than those of A. cruentus. Overall, amaranth leaves contained high amounts of nutritional components. Therefore, amaranth leaves are expected to be useful for the development of a functional food. Moreover, these results will provide fundamental data for advancing sitological value, breeding new cultivars, and promoting leafy vegetable usage.