• 한국산림과학회지
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• 제96권2호
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• pp.170-177
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• 2007

The objectives of this study were to select early, late, and abundant flowering trees of black locust from domesticated and introduced cultivars, and prediction of flowering period by calculation of accumulated temperature in spring. Four cultivars (Debreceni-2, Pusztavacs, Jaszkiseri, and Rozsaszin AC) from Hungary and a cultivar from Beijing, China, were introduced, propagated by seed and planted in a seed orchard. For domesticated black locust, 63 cultivars from 10 locations throughout the country were selected and propagated by root cutting. Criteria for selection of domesticated cultivars were abundant flowering, long flowering period, or abundant nectar production with, if possible, straight stems. Accumulated temperature was calculated from data of a nearby weather station by accumulating daily maximum temperature minus 5 degree Celsius from January 1 up to the date reaching 880 degrees. Daily mean temperature was also used to calculate accumulated temperature up to the date reaching 450 degrees. The percentages of two-year and three-year-old flowering trees propagated by root cutting were higher than that of trees propagated by seeds, while four-year-old trees all flowered regardless of propagation methods. Among the domesticated cultivars, all the cultivars from Ganghwa showed abundant flowering with highest nectar production of 6.5 ul per flower, which was 100% more than other domesticated cultivars and 50% more than Debreceni-2 cultivar with highest nectar production among the introduced cultivars from Hungary. At the end of the eight years of observations, two trees of Debreceni-2 cultivars and a tree from Beijing, China were selected for early flowering trees which flowered 2 to 3 days earlier than average trees, while a tree of Debeceni-2 and three trees from Bejing were selected for late flowering trees which flowered 2 to 3 days later than average trees. It is possible to extend the flowering period of black locust by 4 to 6 days by planting early and late flowering cultivars together. Abundant flowering trees were unable to be selected due to severe damages by leaf gall midges which killed many trees and reduced the crown size of the remaining trees in the seed orchard, and which were first found in Korea in 2001 and now damaging most of the black locust forests in Korea. The prediction of flowering period by accumulated temperature indicated that black locust flowered to a peak when accumulated daily maximum temperature reached 880 degrees Celsius, and when daily mean temperature reached 450 degrees.

• 한국작물학회지
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• 제44권2호
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• pp.159-162
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• 1999

This study was carried out to determine the optimum harvest date of unshelled immature peanuts and dried kernels from 60 to 120 days after flowering. Fresh pod yield of spanish-type variety, 'Shaedl-tangkong(SD)' reached a peak of 9,140kg/ ha at 70 (days after flowering(Aug. 13) while that of virginia-type variety, 'Daepoongtangkong(DP)' reached a peak of 8,820kg/ha at 90 days(Sept. 11) after flowering. SD and DP showed maximum fresh kernel yield of 6,090 and 6,470kg/ha at 90 days after flowering (Sept. 11), respectively, while dry kernel yield reached a peak of 3,300 and 3,720kg/ha at 110 days(Oct. 1), respectively. Oil content of SD and DP were the highest at 90 days and 100 days after flowering, respectively and the oil content of two varieties increased rapidly from 60 to 90 days. Tannin content of the seed hull of SD increased continuously until 110 days after flowering while that of DP maximized at 100 days. The tannin content of the two varieties increased rapidly from 60 to 100 days. Total sugar of SD and DP showed highest content at 60 days and 70 days after flowering, respectively and suger content decreased very rapidly until 80 days and after that sugar content kept nearly constant. Oil, tannin and total sugar content of spanish-type SD were higher than those of virginia-type DP.

• Molecules and Cells
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• 제46권11호
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• pp.710-724
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• 2023

The plant defense responses to microbial infection are tightly regulated and integrated with the developmental program for optimal resources allocation. Notably, the defense-associated hormone salicylic acid (SA) acts as a promoter of flowering while several plant pathogens actively target the flowering signaling pathway to promote their virulence or dissemination. Ralstonia pseudosolanacearum inject tens of effectors in the host cells that collectively promote bacterial proliferation in plant tissues. Here, we characterized the function of the broadly conserved R. pseudosolanacearum effector RipL, through heterologous expression in Arabidopsis thaliana. RipL-expressing transgenic lines presented a delayed flowering, which correlated with a low expression of flowering regulator genes. Delayed flowering was also observed in Nicotiana benthamiana plants transiently expressing RipL. In parallel, RipL promoted plant susceptibility to virulent strains of Pseudomonas syringae in the effector-expressing lines or when delivered by the type III secretion system. Unexpectedly, SA accumulation and SA-dependent immune signaling were not significantly affected by RipL expression. Rather, the RNA-seq analysis of infected RipL-expressing lines revealed that the overall amplitude of the transcriptional response was dampened, suggesting that RipL could promote plant susceptibility in an SA-independent manner. Further elucidation of the molecular mechanisms underpinning RipL effect on flowering and immunity may reveal novel effector functions in host cells.

• 한국작물학회지
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• 제46권5호
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• pp.395-400
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• 2001

We investigated the variations of the flowering response to daylength in Perilla crop (var. frutescens). Seventeen accessions of Perilla crop and one accession of weedy type of var. crispa from China, Korea and Japan were cultivated under three daylength conditions, i.e., short-days, natural daylength and long-days. Most accessions of Perilla crop from China, Korea and Japan were divided into three types, early maturing type, intermediate maturing type and late maturing type by their natural flowering habit. In most of the accessions used, the flowering habit was significantly accelerated by short-day conditions and was delayed by long-day conditions. All the accessions of Perilla crops flowered within 57 days under the 10 hrs light treatment, whereas they did not flower at all even at 170 days after sowing under the 16 hrs light treatment. Thus, this finding suggested that there is a relationship between the types of flowering response to daylength and the geographical distribution which determines the planting season in traditional cultivation practices of Perilla crops. Positive correlation was observed between days to flowering and plant height or internode number in both the short-day and natural daylength conditions. Whereas, correlation was negative between days to flowering and inflorescence length or floret number in natural daylength condition, but it was positive in the short-day condition. Therefore, the daylength condition is considered as the most important environmental factor for flowering habit and morphological characters of Perilla crops. Flowering habit is considered as an important key character for the study of geographical differentiation of Perilla crop in East Asia.

• 한국산림과학회지
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• 제79권3호
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• pp.290-301
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• 1990

1983년도(年度) 보고(報告)된 잣나무 수형목(秀型木) 167 clone의 clone 보존원(保存園)에서 1986년(年)부터 1989년(年)까지, 개화시기(開花時期), 개화율(開花率), 개화량(開花量)을 조사(調査)한 결과(結果)를 요약(要約)하면 다음과 같다. 1) 자화(雌花)가 조기개화(早期開花)하는 소수 clone과 웅화(雄花)가 늦게 비산(飛散)하는 소수 clone들 사이에는 자연교배(自然交配) 될 수 없는 clone들도 있었다. 2) 웅화(雄花)의 개화율(開花率)은 낮았으며 자화(雌花)의 개화율(開花率)보다 유전적(遺傳的)인 영향을 많이 받고 있었다. 3) 자화(雌花)와 웅화(雄花)의 대화량(開花量)은 소수 clone에 의하여 영향을 받고 있었다. 4) 자화(雌花)와 웅화(雄花)의 개화량(開花量)은 상호(相互) 상관(相觀)이 없었으며 167 clone중 42 clone은 웅화(雄花)가 개화(開花)하지 않았다. 5) 167 clone의 개화량(開花量)은 L.S.D 5% 검정(檢定)에 의하여 자화(雌花)는 3 group, 웅화(雄花)는 4 group으로 분류(分類)되었다. 6) 주성분(主成分) 분석(分析)에 의하여 자화(雌花)와 웅화(雄花)가 다량개화(多量開花)하는 clone을 선발(選拔)할수 있었다. 7) 자화(雌花)의 개화율(開花率)과 개화량(開花量)을 기준으로 할 때 Juvenile phase 기간(期間)은 접목(接木)후 4년(年)까지 였으며 transition 기간(期間)은 접목(接木)후 5년(年)부터 7년(年)까지 adalt phase 기간(期間)은 접목(接木)후 8년(年)부터였다. 8) 잣나무 접목묘(接木苗)는 실생묘(實生苗) 보다 6년이상(年以上) 빠르게 개화(開花)하였다.

• Journal of Ecology and Environment
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• 제42권2호
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• pp.50-59
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• 2018

Background: Duodichogamy is the rarest form of dichogamy in angiosperms, which is characterized by flowering in the sequence of male${\rightarrow}$female${\rightarrow}$male. Disentangling factors promoting duodichogamy require the discovery of more duodichogamous species in angiosperms. However, extremely limited information on duodichogamous species makes it difficult to make general conclusions. Given the inflorescence morphology and flowering characteristics, the Meliaceae family is highly likely to contain duodichogamous species. Methods: We selected 48 individuals from 20 populations in Korea and investigated their flower morphology, arrangement of flowers by sexual condition within inflorescences, and flowering phases and duration of male and female flowers of Toona sinensis (Meliaceae) for 5 years (2011-2015) to determine if the species shows duodichogamous flowering. Results: Toona sinensis belonging to Meliaceae possessed functionally unisexual flowers with rudimentary parts of the opposite sex. The floral organs in male were larger than those in female, except for ovary length and width. In dichasium, male flowers were observed on primary or lateral branches, whereas female flowers were borne only on lateral branches. Overall, individuals from six different populations flowered in the male${\rightarrow}$female${\rightarrow}$male sequence, thereby male is blooming far longer than female flowers at the level of individual trees (male vs. female = 17-20 days vs. 2-4 days). Conclusions: This is the first study to report a duodichogamously flowering species, T. sinensis, within Meliaceae. Several flowering characteristics observed from T. sinensis may be important clues used to discover additional duodichogamous Meliaceae species. Short flowering period and relatively small number of female flowers, which is analogous to reduced ovule numbers observed in other duodichogamous species, may intensify male-male competition in T. sinensis. This study contributed to narrowing down potential candidates of duodichogamy based on their geographic distributions and flowering time.

• 한국작물학회지
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• 제38권3호
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• pp.201-207
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• 1993

본 연구는 목화의 개화습성과 착삭에 대한 기초자료를 얻고자 비닐 피복재배를 하고 매일 개화 및 착삭에 대한 조사를 하였는데, 그 결과를 요약하면 다음과 같다. 1. 목화의 비닐 피복재배도 26일에 불과하였으며, 낙뢰가 적고 개화되는 확률이 가장 높은 것은 제 4-8 결과지의 제1절과 제2절위였고 그들 개화기는 7월말-8월 상순의 고온기였다. 2. 개화수에 대한 전체 착삭(수확삭)수 비율은 38%였고 제 1-4 결과지의 제 1,2절과 제 5-8 결과지의 제 1절위의 착삭률이 55～80%로 가장 높았으며, 그 외 절위의 착삭율은 현저히 낮았다. 3. 개화수는 7월 25일경부터 8월 8일경 까지 급격히 증가하고, 그 이후에는 감소를 보이며 개화 최성기는 8월 6일-8월 10일의 5일간이었다. 4. 착삭(수확삭)수는 7월 30일까지 개화한 것은 개화수의 증가영향과 일치하나 그 이후의 개화수는 계속 증가하는 반면 착삭수는 점차 감소하는 경향이었다. 5. 개화당일 기상요소중 최고기온 및 일조시수가 개화 및 착삭수와 고도의 정의 상관을 보였다. 6. 각 결과지의 동일절위간의 개화진행 소사일수는 3.6일 이었다.

• 한국작물학회지
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• 제46권2호
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• pp.130-133
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• 2001

The purpose of this study was to investigate the decreased ratio of growth and yield by delayed seeding and flowering because drought of spring season often cause to delay seeding and sprout emergence. Equation of linear regression, y=-11.914x＋818.61 ($R^2$=0.916) and y=-16.96lx＋913.98 ($R^2$=-0.885) were derived from relationship between sowing date and yield of leading variety, Yangbaeckkae in 1999 and 2000, respectively. Yield was decreased by 7, 24, 40, 57, 74%, respectively, according as sowing date was delayed more 5, 15, 26, 36, 46 days than May 15, standard sowing date under the culture mulched with black P.E. film. Number of capsules per plant and length of stem bearing capsule were greatly decreased, while plant height, stem diameter, and day to flowering were affected little by delayed seeding date. Equation of linear regression, y=-0.7081x＋41.04 ($R^2$=0.861) was derived from relationship between flowering date and yield of 33 accessions. Yield was decreased by 7.7, 8.3, 9.2, 10.1, 11.2%, respectively, according as flowering date was delayed more 1, 2, 3, 4, 5 days than July 3, normal flowering date of Yangbaeckkae when it was sown on May 15, and the more flowering date was delayed, the more yield was decreased. Number of capsules per plant and length of stem bearing capsules were greatly decreased, but plant height and harvest index were decreased little by delay of flowering date

• 한국식물학회:학술대회논문집
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• 한국식물학회 1987년도 식물생명공학 심포지움 논문집 Proceedings of Symposia on Plant Biotechnology
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• pp.213-237
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• 1987

In vitro flowering system may minimize the confounded influence of non-floral meristem parts of plants in studying the relationship of a given treatment and flowering responses. We have induced flower buds from plantlets regenerated from zygotic embryo-derived somatic embryos of ginseng, which circumvented the normal 2-year juvenile period before flowering. The result suggests that the adulthood of ginseng root explants in the experiment previously conducted by Chang and Hsing (1980; Nature 284: 341-342) is not prerequired to flowering of plantlets regenerated through somatic embryogenesis. We have also induced flower buds from elongated axillary brandches from cotyledonary nodes by culturing ginseng zygotic embryos, seedlings, and excised cotyledonary nodes. It was found that 6-benzyladenine (BA) supplemented to the medium was essential for flowering, whereas abscisic acid (ABA) was inhibitory. Gibberellic acid(GA3) was also required for flowering when ABA was present with BA in the medium. The results suggest that cytokinins, gibberellins, and inhibitors play primary, permissive, and preventive roles, respective-ly, in the induction of flowering of ginseng. Tran Thanh Van (1980; Int. Rev. Cytol., Suppl. IIA: 175-194) has developed the "thin cell layer system" in which the induction of shoots, roots, or flower buds from epidermal layer explants were controlled by culture conditions and exogenous growth regulators in the medium, Utilizing the thin cell layer system, Meeks-Wagner et al. (1989; The Plant Cell 1: 25-35) have cloned genes specifically expressed during floral evocation. However, the system is too tedious for obtaining a sufficient amount of plant materials for biochmical and molecular biological studies of flowering. We have developed a garlic callus culture system and one obvious advantaging over the thin cell layer system is that an abundant cells committed to develope into flower buds proliferate. When the above cells were compared by two-dimensional gel electrophoresis with those which have just lost the competence for developing into flower buds, a few putative proteins specific to floral evocation were detected. The garlic callus culture system can be further explored for elucidation of the molecular biological mechanism of floral evocation and morphogenesis.hogenesis.

• 화훼연구
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• 제18권4호
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• pp.271-277
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• 2010

본 연구는 춘란 야생 변이종의 육종을 위한 기초 자료를 얻고자 실시하였으며, 야생종의 개화시기를 꽃봉오리, 반개화, 개화, 개화 후 10일, 개화 후 20일의 5단계로 나누어 자가 수분시킨 후 삭과의 형태적 특성과 발아율을 조사한 결과이다. 착과율은 개화 후 20일에 교배한 것에서 100%로 가장 높았고, 삭과의 무게는 반개화 때 교배한 것이 가장 무거웠다. 5단계로 나누어 발아율을 조사한 결과 반개화에서 가장 높게 나타났으며, 교배 후 채종일수를 150일, 165일, 180일의 3단계로 달리하여 발아율을 조사한 결과에서는 교배 후 채종일수를 150일에 파종한 종자에서 5%로 가장 높게 나타났다. NaOCl 처리를 통한 발아율을 조사한 결과에서는 2%로 처리한 것에서 53.3%의 발아율을 보여 가장 좋은 결과를 나타내었다.