An early heading time gene tentatively designated as 'v' and nonallelic to E₁, E₂, E₃ and Ef-1 was detected in the Taiwanese rice cultivar Taichung 65 (T65) (Okumoto et al. 1992b). This gene remarkably accelerated heading time. The allelism test of this gene to a photoperiod insensitivity gene Se-1^e at the Se-1 Iocus was performed using the progenies from reciprocal crosses between T65 and a heading time tester line ER. The role of this gene in the rice cultivation in Taiwan was also discussed on the basis of photoperiod responses of T65, ER and a heading time tester line LR. T65 was found to have the genotype E₁E₁E₂E₂E₃E₃ vv ef-1ef-1, while ER and LR had the genotypes E₁E₁e₂e₂E₃E₃Se-1^eSe-1^eEf-1Ef-1 and E₁E₁e₂e₂E₃E₃Se-1^uSe-1^uEf-1Ef-1, respectively. ER also carried a rice blast resistance gene Pi-z^t closely linked to Se-1^e on chromosome 6. E₁, E₂, E₃ and Se-1^u were all photoperiod sensitivity genes, and ef-1 at the Ef-1 Iocus remarkably increased the duration of the basic vegetative growth period (BVG). In the F₂, rio distinct transgressive segregants appeared, and the three genotypes (Pi-z^t Pi-z^t, Pi-z^t+, ++) for the Pi-z locus in the F₂ exhibited almost the same range and the same mean for heading time. These facts imply that 'v' is identical with Se-1^e. T65 exhibited a far longer BVG than the two tester lines. The critical day-lengths (CDLs) of T65 and ER were longer than 16 h, while the CDL of LR ranged between 14 h and 15 h : the CDL of LR was shorter than those of T65 and ER. When compared to LR, T65 and ER exhibited a small retarding effect under super optimum photoperiod (RES), and did not differ in RES. These results indicate that the low photoperiod sensitivity of T65 is due to the action of 'v' (=Se-1^e). Since the long BVG of T65 is attributed to the action of ef-1, it is considered that 'v' (=Se-1^e) and ef-1 are very important genes for rice cultivation in Taiwan, where natural day-length is short even in summer and seasonal changes are negligible.

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The goal of this research was to identify molecular markers that could assist in the selection of high shoot regeneration capacity from the progeny of a cross between a tomato cultivar and a ‘peruvianum-complex'. The BC₁F₁ and BC₂F₁ generations between a tomato cultivar, ‘Kyoryoku Ogata Toko' (KOT) and L. chilense PI128644 (together with both the parents and the F₁ hybrids) were used as materials. BC₂F₁ generation was developed by a cross between KOT and a self-compatible BC₁F₁ plant that had high shoot regeneration capacity. Root explants of KOT cultured on an MS medium supplemented with 1 mg/l zeatin riboside did not form any shoots, while those of the PI128644 and the F₁ hybrids showed a high shoot regeneration (SR) rate of more than 80%. The BC₁F₁ generation could be divided into 3 groups (O%, Iess than 30% and more than 80%) for SR rate. The BC₂F₁ generation could be divided only into 2 groups ; about 70% of the plants had O% SR rate and the other 30% had a continuous and non-peak frequency distribution up to 100%. The segregation of the RAPD markers and the acid invertase gene marker (inv^chi) which were specific to the PI128644, were evaluated in BC₁F₁ and BC₂F₁ to determine a possible rela-tionship between these markers and the ability to regenerate shoots. The Mann-Whitney test showed that the RAPD markers, OPA02-1, OPA20-3 and inv^chi were mostly present in the plants with the high shoot regeneration capacity. It was suggested that these three molecular markers are closely linked to the high shoot regeneration gene of L. chilense PI128644.

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The inheritance of regeneration ability in anther culture of rice (Oryza sativa L.) was studied using direct regeneration method (subcultureless anther culture) to evaluate the regeneration ability without any influence of the subculture of calli. In anther culture of 176 F₁ combinations, a positive coefficient of correlation between a regeneration rate per anther and coefficient of relationship to Sachikaze with F₁ hybrid was observed. A negative correlation between regeneration rate and coefficient of relationship to Norin I with F₁ hybrid was also observed. In 4 × 4 diallel analysis using Sachikaze (Nipponbare's maternal variety), Norin 1(Koshihikari's paternal variety), Nipponbare and Koshihikari, different genetic effects were observed on different medium. Especially, on the N₆ medium containing 0.1μM 2, 4-dichlorophenoxyacetic acid (2, 4-D), 5μM naphthalene acetic acid (NAA), 70g/l sucrose and 2mg/l glycine, the relationship between Vr and Wr showed that the low regeneration ability was dominant. Nipponbare possesses recessive alleles at almost all the loci. On the contrary, Norin 1 and Koshihikari have dominant alleles at almost all the loci. Additive effect, mean dominance effect and dominance effect due to specific parent were significant. No epistasis was detected. Reciprocal effect was not significant in plant regeneration. In callus formation, there was no significance in both additive and dominant effects on any media tested. It was suggested that different genes were involved in regeneration ability from callus formation ability. No significance in any genetic effects in regeneration was observed on the medium with alanine, although the regeneration rate became higher as a whole by adding the amino acid into the medium. These results suggest that genes or effects of genes for regeneration were varied for different media.

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Two molybdenum cofactor (MoCo)-deficient mutants, C290 and C384, were isolated from 204, 500 M₂ seedlings of rice (Oryza sativa L., ssp. indica, cv. IR30) by means of chlorate-resistance. The two mutations were monogenic and recessive. Biochemical analysis showed that the activities of nitrate reductase (NR) and xanthine dehydrogenase (XDH) in the mutants were considerably lower than in the wild type IR30, which indicated that the two mutants were actually MoCo-deficient types. On the other hand, nitrite reductase (NiR) activity and nitrate content in the two mutants were higher than IR30. An F₁ strain of cross between the mutants was mutant, indicating that the mutations were allelic. However, the mutants were able to complement the defects in two previously isolated mutants involved in the biosynthesis of MoCo, cnx1 and cnx2. Therefore, genes carried by C290 and C384 define a new locus, which was designated c__ofactor for n__itrate reductase and x__anthine dehydrogenase 3 (cnx 3). In contrast to cnx1 mutant, adding 0.5 mM molybdate into growth medium did not recover NADH-NR activity in C290 and C384. Therefore, the cnx 3 gene presumably encodes a different step from cnx1 in the MoCo biosynthetic pathway.

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Differences in amounts of essential amino acids (EAA) after hydrolysis of proteins were examined using milled seeds from 10japonica, 10 indica and 5 javanica cultivars. Many essential amino acids, i.e., histidine (His), threonine (Thr), isoleucine (Ile), Ieucine (Leu), and phenylalanine (Phe) were higher in Gaiya Dhan Tosar, and His, Tbr, valine (Val), methionine (Met), Leu and Phe were higher in Hu-nan-zao than in other cultivars (Duncan's multiple range test, p<0.05). The concentrations of Val, Met, Ile, and Leu were higher in Sasanishiki, and concentrations of Val, Met, Leu, and Phe were higher in Somewake and Calrose 76. The concentrations of Phe were higher in Ambar and concentrations of Met were higher in Dao-ren-qiao. Concentrations of lysine (Lys) were higher in Ambar, British Honduras Creole, Dao-ren-qiao, Gaiya Dhan Tosar, Mao-zu-tao, and Milyang 23. Concentrations of His were higher in Rinnatto 7616. Thus, the next goal may be to examine the genetic behavior of the.se essential amino acids. Concentrations of EAA per kg-dry weight were significantly correlated with amounts of EAA per 1000 brown rice grains. The two rice cultivar groups were correctly discriminated based on concentrations of the EAA. However, only glycine (Gly) significantly contributed to the discriminant function.

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It was attempted to generate transgenic potato plants expressing rat P4501A1 and rat P4501A1/yeast reductase (YR) fused enzyme by the use of Agrobacterium-transformation system. Six regenerated plants for P4501A1 (GC)and twenty plants for P4501A1/YR fused enzyme (GFC) were selected by kanamycin resistance. Southern blot analysis revealed that one of GC plants and ten of GFC plants showed several bands of P450 cDNA or its fused enzyme gene. The GC plant N0.1160 was found to produce a detectable amount of mRNA corresponding to 1.6 kb-P450 cDNA, whereas the GFC plants gave a much less amount of mRNA corresponding to 3.5 kb-P450/YR fused enzyme gene. Western blot analysis showed that the GC plant N0.1160 produced a large amount of a 59kDa protein corresponding to rat P4501A1. No GFC plants gave a detectable amount of a 130kDa fused protein corresponding to rat P4501A1/YR fused enzyme. 7-Ethoxycoumarin O-deethylase and cytochrome c oxidoreductase activities of the transgenic plants were 1.4 to 3.5 and 1.3 to 3.5 times higher than those of the control plants, respectively. [ˆ14C]-Labeled chlortoluron(CT) was more rapidly metabolized through N-demethylation and p-methyl hydroxylation to none or less phytotoxic metabolites in the GC plant N0.1160, while it was also metabolized through N-demethylation in the control plants. In vivo herbicide-tolerant tests revealed that the GC plant N0.1160 was tolerant against the spray of the CT at 10μmol per pot and another herbicide DCMU, [3-(3, 4-dichlorophenyl)-1, 1-dimethylurea], at 2μmol per pot, although the control plant completely died under the same concentrations of both herbicides. Thus, it was found that expression of rat P4501A1 cDNA confer tolerance to the phenylurea herbicides in potato plants.

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A genomic DNA Iibrary was constructed from lO-day-old rice seedlings. We have isolated and sequenced two nuclear genes, rpl13 and rpl24 that encode chloroplast ribosomal proteins (r-proteins) L13 and L24 respectively. The genomic clone of rpl13 spans 3.0kb and contains three introns. The genomic clone of rpl24 spans 3.3kb and also contains three introns. All intron/exon junctions follow the GT/AG rule. In rpl24, the second intron exists between the DNA sequence encoding the chloroplast targeting signal and the mature protein. In rpl13, there is no intron between them but the first intron exists in the NTE (N-terminal extension) which is an extended amino acid sequence from the eubacterial r-protein homologue. The sequences of the 5'-flanking regions of both genes lack a canonical TATA box. However, several putative transcription regulatory motifs reported in spinach and Arabidopsis were also observed in this region of both genes, indicating that nuclear encoded chloroplast r-protein genes of rice have the same transcriptional regulatory system as dicots.

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It has been shown that deep-seeding and ethylene stimulate the elongation of the first internodes in wheat seedlings. In the present study, patterns of inheritance in the elongation of wheat first internodes and coleoptiles responding to deep-seeding and ethylene were examined using three crosses. Length of the coleoptile in F₂ segregants showed a simple unimodal distribution resembling a normal distribution both in deep-seeded and ethylene-treated plants. Except in one cross, however, length of the first internode in F₂ segregants showed a unimodal distributions with large transgressive segregation on the shorter length side in deep-seeded plants and the longer side exceeding the length of parents' first internodes in ethylene-treated plants. These results suggest that ability of plants to respond to ethylene, a regulatory factor for the elongation of the first internode in wheat, can be changed througb genetic recombination.

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Lily(Lilium×formolongi hort.) protoplasts were isolated from meristematic nodular cell clumps using enzyme solution containing different concentrations of silver thiosulfate (STS), embedded in 0.1%(W/V) gellan gum-solidified medium containing half strength mineral glucose of Murashige and Skoog (1962) medium, 4.1μM 4-amin0-3, 5, 6-trichloro-picolinic acid (picloram) and 0.5 M glucose, and cultured at 25°C in the dark. The highest plating efficiency (17.7%) was obtained when the protoplasts were isolated using the enzyme solution containig 10μM STS.

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Genetic analysis of the morphology of silica bodies from motor cells in rice (Oryza sativa L.) was conducted by examining an F₂ population and a set of 3×5 NCII diallel crosses. Segregation for the four morphological characters-vertical length, horizontal length, Iateral length and shape coefficient (b/a)-of silica bodies in the F₂ population showed a countinous and a wide distribution exceeding the ranges of the two parents (Fig.2), suggesting that the morphological characters of silica bodies were quantitative and controlled by several genes. In the NCII diallel analysls, the heterogenelty of W'r+1/2Vr between arrays was not significant for all the morphological characters but b/a, and the heterogeneity of W'r-1/2Vr was not observed for all the characters tested (Table 4). The regression coefficients of W'r on Vr were nearly 0.5 but significantly different from zero (Table 5), indicating that the shape of the silica bodies was controlled by an additive-dominance genetic system. The heritabilities in a broad sense for the four characters were in the range of 0.43-0.73 and those in a narrow sense in the range of 0.29-0.54 (Table 6).

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In order to produce strains with purple color in zonal geranium, the relationship between flower color and pigmentation was examined, and genetic analysis of the pigments was carried out. Purplish red strains were selfed and crossed with white-flowered strains (Table 1). The main anthocyanidins of purplish red strains were pelargonidin(Pg), peonidin (Pn) and malvidln (Mv). In the progenies of Pg-Pn-Mv type, four pigment types appeared i.e. Pg-Pn-Mv type, Pn type, Pn-Mv type and acyanic type (white). On the other hand, progenies of the Pn-Mv type segregated into Pn type, Pn-Mv type and acyanic type. Most of the plants of the Pg-Pn-Mv, Pn and Pn-Mv types gathered in the 7RP, 5RP and 2RP color region, respectively (Fig.2). Then after, crosses were repeat, ed two or three times. However, no plants showing Mv type or purple flowers (9P) were observed. Plants with superior co-pigment effect were not detected, although co-pigmentation occured in petals (Fig.3). A highly negative correlation (r=- 0.636^{* * *}) was obtained between the Mv ratio and the hue values in the Pn-Mv strain (Fig.4). On the other hand, a highly positive correlation between the amount of pigments and lightness, and chroma was observed (Fig. 5). To investigate the cause of the lack of Mv type in the progenies, the genetic analysis of the pigments was carried out. We assumed that the gene of respective pigments was P_g/p_g for pelargonidin, P_n/p_n for peonidin and M_v/m_v for malvidin, and the genes which controlled DFR (conversion from dihydroflavonol to leucoanthocyanidin) and/or LDOX (conversion from leucoanthocyanidin to anthocy-anidin) were E₁/e₁ and E₂/e₂. Consequently, the genotype of the white strains used in the experiment was considered to be recessive homozygote for the P_g and M_v genes, whereas, dominant homozygote for the P_n gene (p_gp_gm_vm_vP_nP_n) (Tables 2, 3). The expression of P_n may be suppressed by the presence of recessive e₁ and e₂. As a result, it was concluded that the genotype of the white flower used in the experiment may not be recessive homozygote and there was no effect of lethal gene on the Mv plants. Furthermore, this assumption was verified based on the crosses between the white-flowered stralns and three wild Pelargonium plants. In the F₁ generation, the Pn pigment could be detected by the recovery of E₁ and E₂ genes from wild species, although Pn pigment was not detected in two wild species (Fig. 6).

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Although the inheritance of cpDNA and mtDNA has been well investigated in Pinaceae, there have been a limited number of reports in other families of coniferous plants. To clarify the inheritance of cpDNA and mtDNA in Chamaecyparis, one of the most important tree genus in Japan, interspecific hybrids of Chamaecyparis spp were investigated. The DNA of four hybrids from C. obtusa and C. pislfera crosses was digested with HindIII and hybridized with the tobacco cpDNA clone, pTB 8. All the hybrids showed the same pattern as the male parent, C. pislfera. The DNA of the hybrids was also digested with BgIIIand hybridized with the PCR-amplified mtDNA gene, cox I. All the hybrids showed the same Southern bybridization pattern as the male parent, C. pislfera. We conclude, therefore, that cpDNA and mtDNA are mainly inherited paternally in Chamaecyparis. We also observed a higher degree of interspecific polymorphism in the mtDNA than in the cpDNA.

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Three monotelosomic alien addition lines (MtAALs:2n=2x+1t) and one monoacrosomic alien addition line (MaAAL:2n=2x+1a) of japonica rice cultivar Nippon-bare, each carrying a single chromosome of a diploid strain of O. punctata (W1514) were isolated from the progenies of respective monosomic alien addition lines (MAAL:2n=2x+1) for chromosomes 2, 4, 7 and 9 of O. punctata. Among them, three were classified as MtAALs carrying extra telocentric chromosomes 2 and 7, and an extra short arm of chromosome 9 in addition to the diploid complement based on the mitotic and meiotic chromosome analysis. The remaining one was similarly classified as a MaAAL carrying an extra acrocentric chromosome consisting of a complete short arm and a heterochromatic proximal region of the long arm of chromosome 4. Three MtAALs were designated as MtAALs 2, 7, and 9S (short arm of chromosome 9), respectively and one MaAAL was designated as MaAAL 4S^4L. Their morphology, seed fertility and the transmission rates of the extra chromosome were compared with those of the respective primary trisomics and MAALs. The plant morphology of MtAAL 2 and MaAAL 4S^4L was similar to that of the respective MAALs, while the plant morphology of MtAAL 9S was similar to that of the disomics. The plant morphology of MtAAL 7 was similar to that of the secondary trisomics for the short arm of chromosome 7. The seed fertility was higher than that of the respective MAALs, suggesting that the addition lines carrying a small chromosome fragment such as telosome or acrosome could give rise to functional gametes. The transmission rates of the extra chromosome were similar to those of the respective MAALs. Most of the PMCs in the MtAALS and the MaAAL showed a 12II + 1I (telosome or acrosome) configuration at the diakinesis and first metaphase. These facts suggest that the extra telocentric or acrocentric chromosomes originated from a misdivision of an alien univalent at anaphase I or anaphaseII of the respective MAALs and the following chromosome breakage.

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