• Korean Journal of Plant Tissue Culture
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• v.22 no.5
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• pp.261-266
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• 1995

This study was carried out to develop new varieties which are dwarf and tolerant to winter cold in the Aurantioideae by intergeneric crossing. to do that, the reciprocal crosses of Hwanggeumyooza and trifoliate orange, yooza and trifoliate orange were done and in vitro immature ovule culture of their hybrid was carried out .The callus formation from immature ovule was good in order of Hwanggeumyooza, Hwanggeumyooza $\times$ tifoliate orange, yooza, and trifoliate orange and best at 1 to 3 mg/L NAA+0.5mg/L zeatin on MT medium. In vitro germination percentage of 20week old hybrid of Hwanggeumyooza $\times$ tifoliate orange and trifoliate orange $\times$ Hwanggeumyooza were 41.3% and 37.7, respectively. The phenotype of hybrid (95%) of Hwanggeumyooza $\times$ trifoliate orange and that (100%) of trifoliate orange $\times$ Hwanggeumyooza were similar to that of trifoliate orange. After Hwanggeumyooza was pollinated by pollens of trifoliate orange, the pollen tubes grew on stigma after 3h of pollination and entered into micropyle after about 24~28 h. One gamete in pollen was fused with polar nuclei after 2 days and other one fused with egg nucleus at 3days after pollination. The fruit set percentage by intergeneric crossing was 14.0% in Hwanggeumyooza $\times$ trtfoliate orange and 17.5% in trifoliate orange $\times$ Hwanggeumyooza. The fruit set percentages of Hwanggeumyooza. and trifoliate orange were 34.2% and 39.5% by artificial self-fertilization, 34.2% and 39.5% by artificial cross fertilization, 3.1% and 1.4% by parthenocarpy and 13.0% and 3.0% by natural fertilization, respectively. The somatic and gametic chromosome numbers of Hwanggeumyooza, yooza, and trifoliate orange were 2n=18 and n=9.

• Korean Journal of Plant Resources
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• v.36 no.4
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• pp.402-412
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• 2023

Peucedanum japonicum Thunberg is a biennial plant that usually flowers and dies after seed setting at 2^nd year. We inspected the flowering and fertilization characteristics to establish the breeding system. The plant forms complex umbel inflorescences consisting of multiple umbellets and numerous flowers. Each flower is bisexual but allogamous because of protandry. A flower bloomed for three days with matured pollen and no stigma appearance. Inspection of pollen tube growth indicates that the pollen viability can be maintained for up to 3~7 days after first flowering (DAF). In a umbellet, flowers bloomed during 1~5 DAF and the pollen maintained viability during 3~10 DAF, and the pistil developed and maintained fertility during 8~12 DAF. Theoretically, self-pollination can be possible during 8~10 DAF in the same umbellet. Approximately 4.4% of seeds were developed by self-pollination among flowers in an enveloping solitary umbel. There is at least a 9~10 days difference for the development of an umbel with another umbel at the next branch, which indicates pollination can be permitted between different branches in an individual plant. Finally, we have established a rapid breeding method to shorten the breeding cycle to one year from two years by integrating the flowering and pollination characteristics.

• Korean Journal of Agricultural and Forest Meteorology
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• v.8 no.3
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• pp.169-173
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• 2006

This study used loess from the source region of Asian dust (a desert area in China) to analyze the effects of Asian dust on fruiting and fruit quality in Korean fruit trees. Asian dust and loess from the source region were highly alkaline compared to average Korean field soil. Organic material contents of Asian dust were about three times as high as that of the average field soil. Loess was dusted onto the stigma of apple, pear, and peach trees. fruiting, seed number, fruit quality and pollen tube elongation were investigated. Pollination and fertilization were not influenced while pollen tube elongation was slightly influenced. Consequently, fruiting, seed number and fruit quality were not affected by the dusting treatment.

• FLOWER RESEARCH JOURNAL
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• v.19 no.4
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• pp.231-237
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• 2011

In this study, we performed ovule culture after reciprocal crosses of two Alstroemeria accessions and investigated genetic contribution of parents by using RAPD markers. The best method was half-ovule culture on MS medium supplemented with $60g{\cdot}L^{-1}$ sucrose and $2.2g{\cdot}L^{-1}$ gelrite at 14 days after pollination. Embryos began to germinate after 6 weeks of culture. The complete plantlets were formed after 4 months of culture. In eight progenies and two parental cultivars, 59 polymorphic bands were obtained out of 89 total bands by RAPD analysis using 7 primers. Eight $F_1$ progenies from the crosses between two accessions using reciprocal crosses showed 1:1 contribution of maternal and paternal parents. It is confirmed that $F_1$ progenies were obtained from parental accessions by using RAPD markers. We conclude this cross combination showed pre-fertilization barriers with incompatibility between stigma or style, and pollen because progeny number was different in each cross combination. Thereby, it warrants overcoming pre-fertilization barrier together with post-fertilization barrier in order to broaden the heterozygosity within progeny populations in Alstroemeria breeding program.