渡辺 均

国内で使用される生薬の9割を輸入に頼る日本では,近年になり生薬の国内生産が推進されている。2021年8月に第71回学術総会が東北支部主幹で開催された際,特別企画として東北地方における薬用植物栽培と生薬生産の歴史と現況について調査報告を行った。東北地方で薬用植物栽培が拡大したのは江戸時代享保年間以降で,会津のオタネニンジン,出羽のベニバナなどが栽培に成功し全国に流通した。現代の調査では,栽培を伝承し地域振興に活用したり,全く新たに栽培を開始した地域・品目もみられた。栽培事業を継続・拡大するため産官学による連携体制が形成されていた。また,生薬だけでなく,食品・化粧品・織物にも販路を拡大する模索が行われていた。生薬としての流通には多くの課題が残るが,本調査で東北各地での薬用植物栽培の工夫を明らかにすることができた。本調査結果は動画として学会会員専用ホームページにて公開されている。(著者抄録)

<jats:p>The occurrence of tipburn is a severe problem in horticulture crop production. A previous study suggested that, in lisianthus, tipburn is caused by imbalanced calcium (Ca) distribution. However, there are few studies on the effects of other cations on tipburn incidence in lisianthus cultivars. In this study, to determine the effect of Magnesium (Mg) concentration in nutrient solution on tipburn incidence and Ca and Mg acquisition, three lisianthus cultivars (‘Celeb Wine’: CW, ‘Reina White’: RW, and ‘Voyage Peach’: VP) were cultivated under different Mg concentrations in nutrient solution (12 ppm, 34.7 ppm, and 75.4 ppm). Under high nutritional Mg concentrations, CW and RW had significantly decreased tipburn severity, while VP showed no significant differences in tipburn severity among the treatments. Total Ca concentrations in all cultivars significantly increased at higher nutritional Mg concentrations, which indicated that Mg application in lisianthus cultivars promoted Ca acquisition. Furthermore, it was suggested that CW and RW had the ability to distribute increased Mg to the tip of the upper leaves, thereby promoting Ca distribution. Thus, a decrease in tipburn severity in CW and RW at higher nutritional Mg concentrations appeared to occur.</jats:p>

<jats:p>Occurrence of tipburn is a severe problem in the production of lisianthus cultivars. Previous studies have shown excessive Ca accumulation in the roots of tipburn-damaged cultivars, where the distribution of Ca to the tips of the top leaves is inhibited. However, few studies have investigated the association between Ca accumulation and gene expression in horticultural crops. To provide a list of candidate target genes that might be causing the excessive Ca accumulation in roots, we focused Ca2+ transporter and pectin methylesterase (PME) genes and RNA-seq of upper leaves and roots in tipburn-occurrence cultivar (“Voyage peach”: VP) and non-occurrence cultivar (“Umi honoka”: UH) was conducted. In both the upper leaves and roots of VP, genes encoding the glutamate receptors (GLRs), cation/Ca2+ exchangers 4 (CCX4), Na+/Ca2+ exchanger-like protein (NCL), and PMEs were upregulated, and a gene encoding the cyclic nucleotide-gated ion channel 9 (CNGC9) was downregulated. In contrast, genes encoding the vacuolar cation/proton exchanger 5 (CAX5), calcium-transporting ATPase 1 and 12 (ACA1 and ACA12) showed differential expression in each organ. Among them, only CAX5 was upregulated and ACA12 was downregulated in the roots of VP. Based on these results, we suggested that CAX5 and ACA12 are the candidate genes causing the excessive Ca accumulation in the roots of tipburn-occurrence lisianthus cultivars. Future studies should investigate the temporal changes in gene expression using quantitative PCR and conduct functional analysis of candidate genes in tipburn-damaged lisianthus cultivars.</jats:p>

<jats:p>In lisianthus cultivars, the occurrence of tipburn is known to adversely affect quality and yield. However, information concerning the responses of tipburn incidence to different levels of Ca is limited. In addition, only a few studies have investigated the effect of potassium (K) concentration on Ca acquisition and distribution in lisianthus. To address this knowledge gap, we investigated tipburn incidence in three lisianthus cultivars (Umi honoka (UH), Reina white (RW), and Voyage peach (VP)) and the Ca and K concentrations in them under different concentrations of Ca supply (40, 80, and 120 ppm). These cultivars exhibited different responses to different concentrations of Ca supply. Tipburn was not observed in UH. In RW, tipburn incidence and severity significantly decreased with an increase in nutritional Ca concentration, because the Ca concentration in the tips of the top leaves significantly increased with Ca concentration. By contrast, in VP, tipburn incidence under all treatments was 100%, and there was no significant difference in the Ca concentration in the tips of the top leaves among the treatments, but the total Ca concentration significantly increased. VP was the only cultivar that significantly acquired and accumulated more Ca in the roots with an increase in nutritional Ca concentration. Overall, excessive Ca accumulation in the roots under high-Ca conditions inhibits the distribution of Ca to the tips of the top leaves and eventually manifests as tipburn in the cultivar. In addition, our results suggested that the content ratio of K in the nutrient solutions did not prevent Ca acquisition and distribution in lisianthus cultivars and that the K concentration has a negligible effect on the occurrence of tipburn.</jats:p>

【目的】日本の灸治療に用いられるモグサの国内生産量の低下に伴い、モグサ製造用ヨモギの安定供給に向けて、ヨモギの栽培効率やモグサの生産性を向上させる必要があると考えられる。そこで、国内生産に有用なヨモギ系統を明らかにするため、全国各地より収集した国内自生系統の形態評価、および生葉から製造したモグサの品質を比較することにより、効率的栽培への適性に関わる形態と葉乾燥重、およびモグサ収得率を指標として各系統を評価した。【対象と方法】国内127地点より採取したヨモギArtemisia princepsおよびオオヨモギArtemisia montanaの栽培個体を対象に、1.モグサ製造評価としてモグサ収得率、2.モグサ品質評価としてクロロフィル含有量および燃焼時の最高温度、3.ヨモギ形態評価として草姿に関わる形質、葉乾燥重、葉の背軸面の明度を調査した。各系統の形態および性質について比較するため、統計処理として主成分分析に供した。【結果】品質評価の結果、多様なクロロフィル含有量および燃焼時の最高温度が示され、国内系統においても幅広いモグサ品質を示すことが確認された。形態評価における主成分分析の結果、22系統が葉面積が大きく収穫が容易で効率的栽培に適した系統であることに加え、毛茸の量が多くモグサ収得率に優れ、全系統の葉乾燥重の基準値を上回る系統として抽出された。これらの系統には、従来の採取地域以外に、これまで利用されていなかった地域の系統が含まれることが確認された。今後、これらの系統を利用することで、各地域におけるモグサ用ヨモギの国内生産量の向上に繋がると考えられた。【結論】ヨモギの国内自生系統における形態、葉乾燥重、およびモグサ製造後の品質評価により、効率的栽培に適しており、葉乾燥重およびモグサ収得率に優れた灸利用に適する国内自主系統が抽出された。そのうち、従来用いられてきた採取地域における系統以外に、新たな灸利用への可能性が期待できる系統が確認された。(著者抄録)

<jats:p>Tipburn (calcium (Ca) deficiency disorder) is a major problem in the production of lisianthus cultivars. However, few studies have investigated the influence of different Ca concentrations in nutrient solution on tipburn incidence and Ca acquisition and distribution. Thus, it remains unclear why some cultivars exhibit tipburn under high Ca concentrations. To address this, we used three lisianthus cultivars ‘Azuma-no-Kaori’ (AK), ‘Celeb Wine’ (CW), and ‘Voyage Yellow’ (VY) and compared tipburn incidence and Ca acquisition and distribution under different Ca concentrations in a nutrient solution (low (40 ppm), moderate (80 ppm), and high (120 ppm) Ca). Tipburn severity and incidence in AK and VY significantly decreased with increasing nutritional Ca concentrations; the Ca concentrations in each organ and Ca acquisition competence (RGRCa) increased at higher nutritional Ca concentrations. In contrast, tipburn incidence in CW was 100% for all treatments. In CW, Ca acquisition competence and Ca concentrations in most organs increased with increasing nutritional Ca concentrations, but the Ca concentrations in the tips of the upper leaves did not differ significantly between treatments. Thus, our results suggest that the cause of tipburn under sufficient Ca conditions is an inability of the plant to distribute Ca to the tips of its upper leaves.</jats:p>

<jats:p>Tipburn is a major problem for the production of lisianthus (Eustoma grandiflorum (Raf.) Shinn.) cultivars. Relative air humidity is regarded as a key environmental factor affecting tipburn severity in commercial crops. However, there are limited studies comparing the occurrence of tipburn and calcium (Ca) distribution in lisianthus cultivars under different relative air humidity conditions. Accordingly, we investigated the effect of relative air humidity on tipburn severity, transpiration rate, and Ca content in seven lisianthus cultivars. Under a high humidity treatment (70%), only two cultivars (“Voyage pink” (VP) and “Azuma-no-kaori” (AK)) showed significantly higher tipburn severity than those under a low humidity treatment (50%), which suggests that high humidity conditions do not always increase tipburn severity in lisianthus. Transpiration rates of all cultivars, except for AK, were either significantly lower under the high humidity treatment than under the low humidity treatment, or did not vary significantly between the treatments. In contrast, total Ca concentrations in all cultivars, except for “Piccolosa snow” (PS), were significantly higher under the high humidity treatment than under the low humidity treatment. These results suggest that Ca acquisition and distribution in lisianthus cultivars are strongly influenced by Ca uptake from root pressure.</jats:p>

漢方製品の使用量と金額は近年増大しているが、輸入生薬単価の上昇と保険薬価低下のために、漢方薬を扱う業界には長期低落傾向がみられる。生薬国内生産はこの30年間減少し続けているが、状況改善への試みがなされている。福島県の会津産人参生産量は153トンから8トンに減少したが、圃場の拡大と栽培期間短縮の研究が開始された。奈良県では生産から販売までの一貫体制の構築に取組み、大和当帰を用いた新たな商品開発販売のため、生産者、製薬・食品メーカー、大学研究機関による協議会が活動している。また薬用作物の国内生産に向けて、農林水産省、厚生労働省ならびに日本漢方生薬製剤協会は、3年間にわたり生産者と製薬各社とのマッチング会議を各地で開催してきた。漢方による医療費削減のためには、漢方製剤だけでなく煎薬などの生薬を直接用いた治療のできる医療体制が必要である。生薬国内生産コストを賄う施策に関する議論が望まれる。(著者抄録)

To evaluate and describe the current status of Calibrachoa cultivars as bedding plants, the seasonal flowering of 91 commercial cultivars were compared to those of natural species using principal components analysis. The predominant flowering of the cultivars, that is, floriferous in late spring to early summer with a tendency to reduce flower production toward winter, seems to have remained unchanged from that of natural species. However, properties desired in bedding plants, such as early flowering and continuous flowering under short-day and/or low temperature conditions, appear to have been improved in a considerable number of cultivars, although there is still room for improvement. Seasonal and total floral counts were higher in many cultivars compared to natural species. Several natural species were selected for their unique flowering ability and should be evaluated as gene resources for improving the flowering of Calibrachoa cultivars. (C) 2010 Elsevier B.V. All rights reserved.

To study the morphological diversity of the Popular ornamental crop Calibrachoa, traded since the 1990s, floral and vegetative characters of 91 commercial cultivars were compared to those of natural species. Floral colours were classified according to the ISCC-NBS system and the CIE LAB system. The numerical data obtained by measuring 19 floral and vegetative characters was tested with principal component (PC) analysis. Floral colour classes of commercial cultivars were divided into 37 groups according the ISCC-NBS system, whereas those of natural species were divided into 9 groups. These tendencies were readily observable in the scatter diagrams of the a* vs. b* values and the C* vs. L* values. As the result of PC analysis, six PCs were obtained. For PC4, which negatively correlated with the degree of nocturnal corolla limb closure, the majority of natural species showed negative scores whereas the majority of cultivars had positive PC4 scores. In terms of PC2 (flower size), PC3 (growth form), PC5 (floral shape) and PC6 (leaf shape), natural species were dispersed in a range wider than the cultivars. These results suggest that Calibrachoa cultivars possess more highly variable floral colour than natural species, and breeding programmes to diversify the floral colour seem to have progressed rapidly. The tendency of natural species to close the corolla limb toward evening has been removed almost completely from the cultivars. The floral size, growth form, floral shape and leafshape of the cultivars were rather uniform compared to those of natural species. (C) 2009 Elsevier B.V. All rights reserved.

Petunia axillaris occurs in temperate South America and consists of three allopatric subspecies: axillaris, parodii, and subandina. Previous studies have revealed that subsp. axillaris is self-incompatible (SI), subsp. parodii is self-compatible (SC) in Uruguay, and subsp. subandina is SC in Argentina. The SI/SC status over the entire distribution range is not completely understood, however. The objective of this study was to examine the overall SI/SC status of the respective subspecies in comparison with floral morphology. The results confirmed that subsp. parodii and subsp. subandina were SC throughout the distribution range, and that subsp. axillaris was also SC in Brazil and in most of the Argentinean territory. The SI P. axillaris occurs in the natural population only between 34 and 36 S, along the eastern shore of South America. The Brazilian and Uruguayan subsp. axillaris differed in SI/SC status and floral morphology. We discuss the cause of this difference.

In order to identify genetic resources for breeding fragrant petunias for use as bedding plants, volatile compounds released by day from the flowers of 40 commercial Petunia hybrida cultivars were analyzed using a solid-phase micro-extraction technique coupled with GC-MS. The three cultivars with solid deep-blue flowers that accumulate malvidin in corollas with high tissue pH were found to emit abundant iso-eugenol as the principal floral fragrance. Several other cultivars that emitted considerable amounts of methylbenzoate and/or benzylbenzoate from the flower were also identified. Association between the floral fragrance and the other floral traits such as floral anthocyanin composition and corolla-tissue pH was discussed. (c) 2005 Elsevier B.V. All rights reserved.

Background and Aims Petunia inflata has been treated taxonomically in various ways: it has been described as an independent species, treated as a synonym of P. integrifolia, and also regarded as a subspecies of P. integrifolia. The present study was designed to resolve the ambiguity involving the P. integrifolia complex (P. integrifolia plus P. inflata). Methods Tentative identification (either integrifolia group or inflata group) was carried out in the field based on the observation of live specimens at the restricted type localities. The accuracy of the tentative identification was later tested with principal component and cluster analyses of data obtained by measuring 21 morphological characters on cultivated live specimens sourced from 113 natural populations of the P. integrifolia complex in Argentina, Brazil, Paraguay and Uruguay. Key Results There was a clear, statistically significant gap between the morphological measurements of the two groups, ensuring the accuracy of identification carried out in the field except for a probable hybrid swarm. Previously, the condition of the pedicel in the fruiting state was considered an important character distinguishing between these two groups; however, the condition of the pedicel was rather variable in the integrifolia group. The two groups were found to have geographically distinct distributions: the integrifolia group occurred in southern regions, whereas the inflata group occurred in northern regions. Conclusions Based on the available evidence, it is suggested that the two groups are allopatric species, P. integrifolia and P. inflata, in agreement with the opinion of Fries (1911).

Background and Aims The phylogenetic relationships of Petunia sensu Jussieu ( Petunia sensu Wijsman plus Methods Phylogenetic trees of 52 taxa of Petunia sensu Jussieu were constructed using restriction fragment length polymorphism ( RFLP) of chloroplast DNA digested with 19 restriction enzymes and hybridized with 12 cloned Nicotiana chloroplast DNA fragments as probes. Key Results In all, 89 phylogenetically informative RFLPs were detected and one 50% majority consensus tree was obtained, using the maximum parsimony method, and one distance matrix tree, using the neighbour joining method. Petunia sensu Wijsman and Calibrachoa were monophyletic sister clades in both trees. Calibrachoa parviflora and C. pygmaea, previously thought to differ from the other species in terms of their cross-compatibility, seed morphology, and nuclear DNA content, formed a basal clade that was sister to the remainder of Calibrachoa. Several clades found in the phylogenetic trees corresponded to their distribution ranges, suggesting that recent speciation in the genus Petunia sensu Jussieu occurred independently in several different regions. Conclusions The separation of Petunia sensu Wijsman and Calibrachoa was supported by chloroplast DNA analysis. Two groups in the Calibrachoa were also recognized with a high degree of confidence.

We previously identified both self-incompatible and self-compatible plants in a natural population of self-incompatible Petunia axillaris subsp. axillaris, and found that all the self-compatible plants studied carried either S-C1- or S-C2-haplotype. Genetic crosses showed that S-C2 was identical to S-17 identified from another natural population of P. axillaris, except that its pollen function was defective, and that the pollen-part mutation in S-C2 was tightly linked to the S-locus. Recent identification of the S-locus F-box gene (SLF) as the gene that controls pollen specificity in S-RNase-based self-incompatibility has prompted us to examine the molecular basis of this pollen-part mutation. We cloned and sequenced the S-17-allele of SLF of P.axillaris, named PaSLF17, and found that S-C2 S-C2 plants contained extra restriction fragments that hybridized to PaSLF17 in addition to all of those observed in S-17 S-17 plants. Moreover, these additional fragments co-segregated with S-C2. We used the S-C2-specific restriction fragments as templates to clone an allele of PaSLF by PCR. To determine the identity of this allele, named PaSLFx, primers based on its sequence were used to amplify PaSLFalleles from genomic DNA of 40 S-homozygotes of P. axillaris, S-1 S-1 through S-40 S-40. Sequence comparison revealed that PaSLFx was completely identical with PaSLF19 obtained from S-19 S-19. We conclude that the S-locus of S-C2 contained both S-17-allele and the duplicated S-19-allele of PaSLF. S-C2 is the first naturally occurring pollen-part mutation of a solanaceous species that was shown to be associated with duplication of the pollen S. This finding lends support to the proposal, based on studies of irradiation-generated pollen-part mutants of solanaceous species, that duplication, but not deletion, of the pollen S, causes breakdown of pollen function.

The relative floral anthocyanidin contents of 195 commercial petunias with floral colours other than white and yellow were determined using HPLC, and the presence of five anthocyanidins {cyanidin, peonidin, delphinidin, petunidin, and malvidin} was confirmed. Pelargonidin was not detected, and delphinidin was not a major component. Using a principal component analysis of the relative anthocyanidin contents, the petunias were classified into three phenotype-groups accumulating cyanidin, peonidin, or malvidin, {plus petunidin} as the major anthocyanidin. A fourth phenotype was segregated in the progeny obtained by self-pollinating an F-1 hybrid of the malvidin group; this accumulated delphinidin 3-glucoside in a markedly crumpled corolla-limb (delphinidin group). Such inferior floral traits, associated with the accumulation of delphinidin 3-glucoside, are thought to be the driving force that removed the delphinidin group from commercial petunias. A comparison of flowers of the delphinidin group and those of the other groups may provide a useful tool towards a deeper understanding of how anthocyanin biosynthesis relates to normal development of the corolla. (C) 2004 Elsevier Ltd. All rights reserved.

Two new acylated peonidin glycosides and three known acylated or non-acylated peonidin glycosides were identified in the flowers of 17 commercial pink petunias: peonidin 3-O-[6-O-(4-O-(4-O-(6-O-(trans-caffeoyl)-beta-D-glucopyranosyl)-trans-p-coumaroyl)-alpha-L-rhamnopyranosyl)-beta-D-glucopyranoside]-5-beta-[O-D-glucopyranoside], peonidin 3-O-[6-O-(4-O-(4-O-(beta-D-glucopyranosyl)trans-p-coumaroyl)-alpha-L-rhamnopyranosyl)-beta-D-glucopyranoside]-5-O-[beta-D- glucopyranoside], peonidin 3-p-coumaroylrutinoside-5-glucoside, peonidin 3-caffeoylrutinoside-5-glucoside, and peonidin 3-rutinoside-5-glucoside.

The floral pigment profiles of twenty Calibrachoa cultivars were determined and compared with the profiles of selected Petunia cultivars. Calibrachoas could be divided into two groups based on high (177-871 mug g(-1) FW) and low 2-9 mug g(-1) FW) carotenoid content; the groups were represented by yellow and white flowers, respectively. In addition to yellow cultivars, the high carotenoid content group included vivid-red and vivid-purplish-red cultivars that were characterized by a low floral pH of 4.5-4.8 and accumulation of delphinidin and petunidin, respectively, as the major floral anthocyanidin. In addition to cultivars with white flowers, the low carotenoid content group contained vivid-purple and vivid-red-purple cultivars that were characterized by higher (pH 5.4-5.7) and intermediate (pH 4.8-5.3) corolla pHs, respectively, and accumulation of malvidin. The strategies of calibrachoas and petunias for expressing yellow and red flowers were found to differ. For yellow flowers, calibrachoas use carotenoids, whereas petunias use flavonols plus carotenoids. For red flowers, calibrachoas use carotenoids, delphinidin and lower corolla pH, whereas petunias use cyanidin and lower corolla pH.

Although Petunia axillaris subsp. axillaris is described as a self-incompatible taxon, some of the natural populations we have identified in Uruguay are composed of both self-incompatible and self-compatible plants. Here, we studied the self-incompatibility (SI) behavior of 50 plants derived from such a mixed population, designated U83, and examined the cause of the breakdown of SI. Thirteen plants were found to be self-incompatible, and the other 37 were found to be self-compatible. A total of 14 S-haplotypes were represented in these 50 plants, including two that we had previously identified from another mixed population, designated U1. All the 37 self-compatible plants carried either an S-C1- or an S-C2-haplotype. SC1SC1 and SC2SC2 homozygotes were generated by self-pollination of two of the self-compatible plants, and they were reciprocally crossed with 40 self-incompatible S-homozygotes (S1S1 through S40S40) generated from plants identified from three mixed populations, including U83. The SC1SC1 homozygote was reciprocally compatible with all the genotypes examined. The SC2SC2 homozygote accepted pollen from all but the S17S17 homozygote (identified from the U1 population), but the S17S17 homozygote accepted pollen from the SC2SC2 homozygote. cDNAs encoding S-C2- and S-17-RNases were cloned and sequenced, and their nucleotide sequences were completely identical. Analysis of bud-selfed progeny of heterozygotes carrying S-C1 or S-C2 showed that the SI behavior of S-C1 and S-C2 was identical to that of S-C1 and S-C2 homozygotes, respectively. All these results taken together suggested that the S-C2-haplotype was a mutant form of the S-17-haplotype, with the defect lying in the pollen function. The possible nature of the mutation is discussed.

The carotenoid contents of the flowers of 35 commercial petunia cultivars having non-yellow flowers (non-yellow cultivars) were compared with those of five cultivars having yellow flowers (yellow cultivars). All yellow cultivars were confirmed to contain large quantity of carotenoids such as β-carotene, lutein, zeaxanthin as well as unknown carotenoids. The carotenoid content in 'Summer Sun' was prominent and seemed to be rather exceptional among yellow cultivars examined. Carotenoid contents in the flowers of several cultivars having red colour, such as 'Celebrity Red' and 'Celebrity Red Morn', and other colours, such as 'Baccara Burgundy Picotee', were revealed to be comparable with those of yellow cultivars except 'Summer Sun'. The existence of considerable amount of carotenoid in the flower was also detected by direct measurement of absorbance spectra for the fresh flower. The possible involvement of carotenoid in the floral colour of garden petunia, as an additional element, is discussed.

The applicability of ovule culture was examined in reciprocal crosses between the diploid species D. grandiflorum L. and the tetraploid cultivar D. hybridum 'Galahad'. An interspecific hybrid plant of D. hybridum 'Galahad' x D. grandiflorum was obtained, and hybridity was confirmed by chromosome counting. The hybrid was different from the parents in flower color and size but intermediate between the parents in leaf shape. The hybrid showed low pollen fertility and failed to produce viable seeds by either self- or backcross-pollination using fertile pollen grains from its parents. The applicability and efficiency of the ovule culture technique for genetic improvement of the genus Delphinium through interspecific hybridization between different ploidies is discussed.

The overall status of self-incompatibility, as assessed by the rate of capsule-set after self-pollination, was investigated in the genus Calibrachoa (Solanaceae). Thirty-two species were surveyed using a total of 655 individuals collected in 102 different native populations in Argentina, Brazil, Mexico, and Uruguay. The rate of capsule-set in 278 voucher specimens collected from the same native habitats was also measured to obtain additional information to assess the degree of self-(in)compatibility. Only one species, Calibrachoa parviflora, was self-compatible (SC, autogamous) and the other 31 species were found to be self-incompatible (SI). A mixed population (SI and SC individuals in the same population) was not found. The differentiation of C. parviflora as an autogamous species is associated with a successful occupation of different (riparian) habitats within a larger range of geographic distribution compared to the rest of the species in the principally SI genus of Calibrachoa. © The Botanical Society of Japan and Springer-Verlag 2002.

Petunia axillaris seedlings from 102 localities in Uruguay were examined for the range of morphological variations. When three floral characters and seven vegetative characters that are horticulturally important were measured, they varied significantly between the two subspecies axillaris and parodii, except for plant height and leaf length. Cluster analyses of variations of characters, relative to the population locality, revealed that plant height and width and number of lateral stems segregated into six growth forms: upright, medium, compact, lax, small prostrate, and large prostrate. These growth forms seemed to represent ecotypical groups rather than taxonomical. The relationship between the growth forms and the environment of native habitats are discussed. In addition, we noted the growth forms that have horticultural potentials and their application to breeding.

Cross-compatibility of Petunia exserta, a natural species having red flowers, with 46 taxa of Petunia sensu Jussieu (20 taxa of Petunia sensu Wijsman plus 27 taxa of Calibrachoa) was examined to obtain basic information for the breeding of garden petunias. Petunia exserta completely failed to set capsules when crossed with any species of Calibrachoa. Petunia exserta exhibited unilateral interspecific incompatibility with 15 taxa of Petunia sensu Wijsman: As a seed parent, it could be crossed with all taxa of Petunia except P. occidentalis, but the reciprocal crossings were successful with only five taxa. In the F2 generation of P. exserta hybrid crossed with P. axillaris subsp. axillaris having white flower, individuals having red flowers segregated. F2 progenies contained delphinidin glycosides as the major floral anthocyanin similar to P. exserta. The use of P. exserta as an additional gene resource for improving red flowered garden petunias is discussed.

既に報告したウルグアイにおけるPetunia axillaris subsp. axillarisとsubsp. parodiiの中間型の由来について考察するため,野生種子由来のsubsp. axillarisとsubsp. parodiiから正逆組み合わせのF_1,さらにF_2個体を育成し,花器形態の遺伝様式を調査した。特に,ウルグアイの2亜種を区別する重要な形質でありながら,今まで無視されてきた雄ずいの状態(2強または4強)に注目し,以前の研究者にも取り上げられている花筒長および花冠径とともに計測した。また,花筒長/花冠径比と,Kokubun et al.(1997;植物分類,地理48巻:173-185)の判別関数Z_<12>による判別得点を2次変数として分析に供した。その結果,各形質は量的に遺伝していたが,4強雄ずいはF_1個体には現われず,F_2になって初めて出現し,あたかも劣性遺伝子のようにふるまった。Subsp. axillarisとsubsp. parodiiよりも分散が大きく,それはsubsp. axillarisを母親にしたF_1個体にも継承された。F_1,F_2個体とも,計測値はおおむね両親の値の範囲に分布した。正逆の組み合わせを比較した場合,計測値は母親の値に近く,特にsubsp. axillarisを母親とした場合,subsp. axillarisとF_1・F_2個体の値の分布に重なりが見られた。このことは判別得点についても言え,前報でsubsp. axillarisと判定された群落の中にもsubsp. parodiiの遺伝子が浸透している可能性が示唆された。F_2個体では花筒が長いほど4強雄ずいに近くなる(subsp. parodiiに似る)傾向が示された。Colonia州のLa Plata川沿いに見られた中間型は本研究で得られたF_2個体の一部に似ており,この中間型が雑種起源である可能性が認められたが,FloresおよびSoriano州のNegro川下流域に見られた小輪の花をもつ中間型はsubsp. axillarisとsubsp. parodiiの交雑だけで説明することは難しいと思われた。

ペチュニアなどナス科植物は配偶体型自家不和合性を示すことで知られる。本報では,自家受粉後の着果率を指標として,既知のペチュニア属全分類群(17分類群)を対象とし,86群落由来の1,201個体の自家(不)和合性を調査した。Petunia axillaris subsp. parodii(前報)に加え,subsp. subandina, P. exserta, P. occidentalisを自家和合,残りの全分類群を自家不和合と判断した。P. reitziiには,自家不和合個体のみで構成される群落に加え,自家不和合個体に自家和合個体が一部混ざる群落が認められたが,これはP. axillaris subsp. axillarisの場合と同様,自家不和合機構の破壊によるものと推定された。自家和合分類群はすべて果柄が内曲し,P. axillaris subsp. axillarisとP. integrifolia subsp. inflataを除く自家不和合分類群は果柄が外曲することから,自家不和合性と系統との関連が議論された。ペチュニアの分布域の年間降水量は,東の大西洋沿岸で多く,アンデス山脈に近い西で少ないが,降水量の少ない地域に自家和合分類群が広く分布することと,東部産ながら自家和合性のP. exsertaの特殊な生育環境から,自家和合性が受粉媒介者の機能しにくい環境下でのオプション機能として発達した可能性が議論された。

In order to obtain additional taxonomic information about infraspecific taxa of Petunia integrifolia, we examined reciprocal cross compatibility between combinations of var. integrifolia, var. depauperata, subsp. inflata, subsp. occidentalis, as well as P. axillaris. Subsp. occidentalis completely failed to set capsule when it was used as the pollen parent. Similarly, the crossings in the opposite direction were rarely successful, and the number of hybrid plants obtained was limited. In contrast, all other taxa, including P. axillaris, could be crossed reciprocally with a higher rate of capsule set. The pollen fertility of the subsp. occidentalis hybrid was inferior to that of all the other hybrids. Based on the results of a previous study (Ando et al. 1995) and those of the present one, we treated subsp. occidentalis as an independent species herein.

前2報では, ウルグアイ内のPetunia axillaris2亜種がおおむねリオ・ネグロ川を境に住み分けており, リオ・ネグロ川下流域とラ・プラタ川沿いにはその中間型も見られる事を示した。今回は, 2亜種間の遺伝子浸透をより明確にするために中間型の分布に注目して, ウルグアイ内102地点で採集された種子由来の植物の形態の判別分析を行った。判別分析の典型地として中間型の見られた地域から南北に最も離れた地点を選んだ。Petunia axillaris subsp. axillarisの3郡12地点, subsp. parodiiの典型地としてArtigas郡とSalto郡から16地点を使用した。ステップワイズ判別分析により得られた5判別関数に全102地点の計測値を代入した亜種の判別により, 2亜種がおおむねリオ・ネグロ川を境として分布することが再確認されたが, 中間型とされたものの分布は前報の結果よりも広く, リオ・ネグロ川と平行した南側の地域とSoliano郡全域, Colonia郡のラ・プラタ川沿岸に見られた。このように, 中間型の分布は明確になり, 今後の遺伝資源解析のための基礎的データの一つを提供すると思われる。