In Nepal, about 73% of the vegetable production area is estimated to be covered by hybrid varieties. Most of the hybrid seeds in vegetable crops are imported from abroad. Considering the demand for hybrid vegetable varieties, the National Horticulture Research Centre (NHRC), Khumaltar, Lalitpur has started hybrid breeding of vegetables using a conventional approach since the fiscal year 2003/04. With this effort, the tomato hybrid ‘Srijana’ was developed and registered in 2010. This variety was estimated to cover about 35% of the total tomato cultivated area. Two tomato hybrids, namely ‘Khumal Hybrid Tomato-2 (HRA14 × HRD7) and ‘Khumal Hybrid Tomato-3’ (HRA20 × HRD2), showed good performance and were released in the National Seed Board in 2021. It was found that the heterosis for the yield was 87% in ‘Khumal Hybrid Tomato-2’ and 95% in ‘Khumal Hybrid Tomato-3’ with a potential yield of 70 MT/ha and 60 MT/ha, respectively, under open field conditions. Similarly, a comparative study of 7 tomato hybrids at different research stations was carried out and it showed that F1 (HRA13 × HRD7) could be a potential hybrid for the western region with a potential productivity of 116.8 MT/ha under a protected cultivation system. Hybrid breeding of cucumber was also initiated in the fiscal year 2007/08. A total of 12 crosses in cucumber were performed and two hybrids F1 (HRDCUC004 x RDCUC001), 107 MT/ha and F1 (HRDCUC009 × HRDCUC003) 150 MT/ha were found promising. Hybrid breeding in brinjal, hot pepper and bitter gourd has also been started. Furthermore, key problems and way forward to strengthen hybrid vegetable breeding in Nepal were also discussed.

사료용 옥수수 “DK 7545” 교잡종은 미국의 Dekalb plant Genetics Co., “Garst 8285”는 Garst Seeds Co., 그리고 GW 737은 Crosbyton Co.에서 각각 육성한 품종들이다. 이들 품종들의 수입 사료작물 지역적응성을 검정하기 위하여, 수원과 천안 2개 지역에서, 3개년 동안 생산력을 검정한 결과, 그 우수성이 인정되어 2002년 농협중앙회 수입적응성 심의위원회에서 신규보급품종으로 결정되었으며 이들 교잡

사료용 옥수수 교잡종 Nc+4880은 미국의 "NC+hybrids Co.", Garst 8396 IT은 “Garst Seeds Co.” 회사가 각각 육성한 교잡종들이며, 사료작물 수입적응성을 검정하기 위하여, 수 원과 천안 2개 지역에서, 3개년 동안 생산력을 검정한 결과, 그 우수성이 인정되어 2002년 4월 농협중앙회 수입적응성 심의위원회에서 신규 보급품종으로 결정되었으며, 이들 교잡종 들의 주요 재배적 특성은 다음과 같다. 1. NC+4880 가.

Background: Atractylodes japonica Koidz. and Atractylodes macrocephala Koidz. belong to the family (Asteraceae). Their rhizomes, called white Atractylodes rhizomes, are used in traditional medicine. To address some issues with their cultivation, we recently developed eight hybrid cultivars by interspecific hybridization of A. japonica and A. macrocephala. This study was conducted to screen the hybrid cultivars that have high amounts of active ingredients and yield ability. Methods and Results: Experiments were conducted using the eight hybrid cultivars and A. macrocephala (control cultivar) in the experimental field of the department of Herbal Crop Research located in Eumseong, South Korea. We investigated the growth characteristics of the aerial and underground parts. Among the cultivars, ‘Sanwon’ had the highest rhizome dry weight (53.8 g/plant), followed by ‘Dachul’ (50.0 g/plant). In addition, the content of atractylenolide I, II, III and total active ingredients were investigated using high-performance liquid chromatography. Compared with A. macrocephala, most of the inter-specific hybrid cultivars had a higher content of active ingredients and yield ability. Conclusions: Through study, we established the superior quality of Atractylodes inter-specific hybrid cultivars. In particularly, it was found that ‘Dachul’ may be grown as a superior cultivar, with high amount of active ingredients as well as yield ability.

Background : Atractylodes japonica koidz. (AJ) and Atractylodes macrocephala koidz. (AM) belong to Atractylodes genus (Asteraceae) and their rhizomes are used as traditional medicine ‘Baek-chul’. The ‘Baek-chul’ is considered to be effective for the treatment of stomach disorder, virus, diuresis, inflammation, arthritis and Atractylenolide I, Atractylenolide II and Atractylenolide III are the major active ingredients of these. Previously, we developed 8 hybrid cultivars with disease resistance, high yielding ability and high active ingredients by interspecific hybridization between AJ and AM. In this study, growth characteristics of 8 hybrid cultivars were investigated in RDA experimental field. Methods and Results : Growth characteristics of 8 hybrid cultivars were investigated in RDA experimental field. Among these cultivars, ‘Sanwon’ had the highest fresh weight of rhizome (149.5 g/plant), followed by ‘Dachul’ (145.8 g/plant). Most of hybrid cultivars showed higher fresh weight than and AM (108.7 g/plant). In addition, active ingredients (Atractylenolide I, Atractylenolide Ⅱ and Atractylenolide Ⅲ) were investigated using HPLC. As a result, The sum of active ingredients were the highest in ‘Dachul’ (0.40 ㎎/g) that was 2 times higher than AM (0.22 ㎎/g). Conclusion : In this study, hybrid cultivars showed higher agronomic performance than AM. Particularly, ‘Dachul’ could be the superior cultivar with high atractylenolides as well as high yield ability.

Background : In order to develop new cultivar of hybrid kiwifruit with cold tolerance, high useful components and high quality fruit, we have been crossed ‘Hayward’ (Actinidia deliciosa) with A. arguta. The new hybrid kiwifruit cultivars were 'DM', 'HO', and 'JW'. Actinidia arguta, called hardy kiwifruit, has an edible smooth skin and contains high amounts of sugar and vitamin C. It is native to north China, Korea, and Japan. A. deliciosa are known as kiwifruit and originated in Southwest China. The fruit of A. deliciosa appreciated for its sweet, slightly acidic flesh and high nutritional value, especially due its high content in vitamin C like A. arguta. The cultivar ‘Hayward’ of A. deliciosa occupies the majority of the world kiwifruit cultivated surface, and is the cultivar commercially produced in Korea. However, the kiwifruit producing areas are limited to warm climates region, it can be cultivated in the southern parts of Korea. In our research, several hybrids have been developed to enhance cold tolerance by crossing ‘Hayward’ with domestic species. Methods and Results : In our research, several hybrids have been developed to enhance cold tolerance by crossing ‘Hayward’ with domestic species. Freeze dried the fruit of hybrid kiwifruit was finely ground, extracted twice with methanol (MeOH). The crude extracts of the fruit was analyzed with HPLC for vitamin C and β-carotene analysis. Conclusion : Moisture and carbohydrate contents of hardy kiwi fruit in this study varied from 81.40 - 83.57% and 14.63 - 16.90 g/100 g, respectively. Among new cultivars, JW had higher fat(0.17 g/100 g) and protein(1.33 g/100 g) contents than others. The highest vitamin C and β-carotene content of hardy kiwi fruit were 120.70 ㎎/ 100 g, 0.14 ㎎/kg, respectively in DM.

Self incompatibility (SI) of Cruciferous crop has been studied not only to find out the evolution of the self incompat-ibility system, but also to identify the S haplotypes of the plant materials on the practical breeding programs. It has been reportedtha

Frequent occurrence of off-type plants in a given cultivar has been a serious problem in both breeder's and farmer's fields. An experiment was designed to examine the differences in rate of occurrence of off-type plants among Tongil-type cultivars (high yielding cultivars derived from indica/japonica hybridization) from which the possible cause of higher occurrence of off-type plant in a specific cultivar was deduced. Among five Tongil-type cultivars examined for morphological variant in the field, only one cultivar, Dasanbyeo, had off-type plants. When analyzed with SSR markers, off-type plants showed different band patterns from original cultivar, having several extra bands in addition to cultivar-specific band, suggesting that off-type plants were originated from Dasanbyeo, rather than originated from mixing or mishandling of seed materials with other cultivars. The possible cause of off-type occurrence seems to be natural pollination with other cuItivars adjacent to the original cultivar during seed multiplication. This was supported from the observation that self-crossed progeny of the off type plants showed a wide range of variation of agronomic traits which could not be observed when there was a smaller introduction of genes to the fixed germplasm as happened in the case of cultivar mutation. Another evidence supported this idea that Dasanbyeo showed much of difference in floral organ and behavior to other cultivar to be subjected to higher out-crossing than other cultivars examined.

단순열성 유전자에 의한 GMS민 IR36ms에 가야벼, 남풍벼, 신광벼 및 수원 296 등 4개 한국 수도품종을 각각 4회 연속 Bulk로 교잡시킨 BC3 F2 에서 웅성불임 개체를 얻어서 여기에 각 반복친을 1회 더 Backcross시킨 BC4 F2 세대에서 웅성불임 개체들을 선별하였다. 여기에 각 반복친을 교잡시켜 4품종의 Msms 유전자형을 얻고 이를 다시 BC4 F2 에서 선발한 웅성불임 개체(msms)에 교잡시키므로서 가야벼ms, 남풍벼ms, 신광벼ms 및 수원 296ms를 육성하였다. 이들 4개 웅성불임 계통들의 주당수수, 수당영화수, 출수기 및 수장은 모품종과 차이가 있었으나 웅성불임 계통들의 간장은 모품종에 비하여 단축되었다. 동일한 웅성불임 유전자를 가진 GMS 계통도 반복친에 따라 자연교잡 정도의 현저한 차이가 있었다. 가야벼ms는 11.5%, 남풍벼 ms는 13.1%, 신광벼ms는 1.9% 그리고 수원 296ms는 12.7%의 자연교잡율을 나타내었다. 화분친으로부터 15~90cm 거리 내에서는 가야벼 mS 및 남풍벼ms의 자연교잡율의 거리에 따른 차가 인정되지 않았다.

중공의 CGMS (cytoplasmic-genetic male sterility)를 한국품종으로 이전하여 그들을 MS유지계통으로 쓸 경우 이들이 임성회복친과 교잡되어 발현될 것으로 기대되는 수중의 잡종강 세정도를 중공의 CGMS계통 및 그 유지계통들과의 잡종과 대비하여 조사검토하였다. 그 결과는 다음과 같이 요약된다. 1. 수량의 잡종강세는 heterosis(F1 /MP)로 표현하여 113~221.1% 전체평균 150.5%이었고 hetero-beltiosis(F1 /better p)로 표현하여 86.1~179.8%전체평균 125.3%이였다. 품종군별로는 중공계통들이 가장 높았는데 유지계통들은 MS계통들보다 높았다. 다음으로 높은 것은 임성회복친들이었고 한국품종으로 유지계통들은 가장 낮은 잡종강세를 보였다. 2. 수량구성요소별로 잡종강세를 heterobeltiosis로 표현해 보면 수수는 전체평균 92.7%로 감소되었고 수당입수는 120.0%로 증가했으며 임실율은 103.0%로 유의할만한 변화가 없었고 천립중은 112%로 증가하였다. 증수에 크게 기여한 수당입수와 천립중의 heterobeltiosis를 품종군별로 보면 수량의 그것과 비슷한 경향이었다. 3. 수량구성요소가 수량에 기여한 정도를 임성회복친별 교배조합군별로 검토하기 위하여 경노계수를 계산하였더니 밀양46, 수원294 및 수원287 조합 모두에서 다같이 수당입수가 0.8073~0..8649로 가장 컸고 다음은 천립중으로 0.2000~0.5032이었다. 4. 품종군별 잡종조합의 수량을 교배조합능력이라고 간주하고 이것을 전체평균에 대한 비율로 계산하여 비교했는데 임성회복친 중 밀양46과 수원294는 일반조합능력은 비슷하나 특수조합능력은 차가 있고 S. 287은 일반조합능력이 떨어진다. 유지계통별로는 중공의 유지계통이 가장 높았고 한국유지계통이 가장 낮았다. 중공의 CGMS를 한국품종으로 이전하는데 있어서의 문제점을 검토하였다.