Mutant Cultivars Research Articles

Improvement of soybean through radiation-induced mutation breeding techniques in Korea

Mutation breeding techniques have been used to induce new genetic variations and improve agronomic traits in soybean. In Korea, the Korea Atomic Energy Research Institute (KAERI) has unique radiation facilities to induce plant mutations and has been conducting soybean mutation breeding programmes since the mid-1960s. Until now, the KAERI has developed five soybean mutant cultivars exhibiting early maturity, high yield and seed-coat colour change. In this paper, we review these five mutant cultivars in terms of how to successfully induce unique agronomic characteristics through mutation breeding programmes. A number of induced mutants exhibiting null lipoxygenase enzymes, altered protein patterns or Kunitz trypsin inhibitor activity could serve as genetic resources for the genetic analysis of target genes, and one mutant population has been developed for a reverse genetic study.

Identification of the glucosyltransferase gene that supplies the p-hydroxybenzoyl-glucose for 7-polyacylation of anthocyanin in delphinium.

In delphiniums (Delphinium grandiflorum), blue flowers are produced by the presence of 7-polyacylated anthocyanins. The polyacyl moiety is composed of glucose and p-hydroxybenzoic acid (pHBA). The 7-polyacylation of anthocyanin has been shown to be catalysed by two different enzymes, a glucosyltransferase and an acyltransferase; both enzymes utilize p-hydroxybenzoyl-glucose (pHBG) as a bi-functional (Zwitter) donor. To date, however, the enzyme that synthesizes pHBG and the gene that encodes it have not been elucidated. Here, five delphinium cultivars were investigated and found to show reduced or undetectable 7-polyacylation activity; these cultivars synthesized delphinidin 3-O-rutinoside (Dp3R) to produce mauve sepals. One cultivar showed a deficiency for the acyl-glucose-dependent anthocyanin 7-O-glucosyltransferase (AA7GT) necessary for mediating the first step of 7-polyacylation. The other four cultivars showed both AA7GT activity and DgAA7GT expression; nevertheless, pHBG accumulation was significantly reduced compared with wild-type cultivars, whereas p-glucosyl-oxybenzoic acid (pGBA) was accumulated. Three candidate cDNAs encoding a UDP-glucose-dependent pHBA glucosyltransferase (pHBAGT) were identified. A phylogenetic analysis of DgpHBAGT amino acid sequences showed a close relationship with UGTs that act in acyl-glucose synthesis in other plant species. Recombinant DgpHBAGT protein synthesized pHBG and had a high preference for pHBA in vitro. Mutant cultivars accumulating pGBA had very low expression of DgpHBAGT, whereas expression during the development of sepals and tissues in a wild cultivar showed a close correlation to the level of accumulation of pHBG. These results support the conclusion that DgpHBAGT is responsible for in vivo synthesis of pHBG in delphiniums.

Marker assisted selection for developing high yielding submergence tolerant rice (Oryza sativaL.) genotypes with slender grain

Submergence was a major abiotic stress in rice growing areas, particularly in the rainfed low land ecosystem of eastern India. Tolerance of complete submergence was recognized in some landraces and can be conferred by the Sub1 locus in chromosome 9. Farmers’ adaptation to these landraces and previously developed submergence tolerance genotypes was poor due to either their low yield potential and/or poor grain quality. The purpose of this study was introgressing Sub1 locus from tolerant genotype to high yielding susceptible cultivars with an aim of developing high yielding submergence tolerant genotypes with slender grain preferred by local consumer. During this study fifty lines were selected on the basis of higher yield potential from an advance generation (F4) of a cross between a submergence tolerant, natural mutant (P-1) and submergence susceptible rice cultivar (IR-36). Three already established SSR Primer pairs (RM-265, RM-219 and RM-464A), linked with submergence tolerance were employed to detect p...

Analysis of Factors Affecting Seed Protein Compositions and Protein Contents in Rice of Seed-Protein Mutant Cultivars under Different Cropping Seasons

低グルテリン米水稲品種LGCソフトと低グルテリン・26 kDaグロブリン欠失米水稲品種エルジーシー潤および一般食用水稲品種ニホンマサリを供試して，4カ年延べ8～9作期を設定し，米粒のタンパク質組成と総タンパク質含有率 （TP） の変動要因やその品種間差を検討することで，タンパク質変異米水稲品種の米粒の易消化性タンパク質含有率 （DP） を低レベルに制御するための栽培管理上の要点を明らかにしようとした．重回帰分析の結果，DPは，TPと総タンパク質に占める易消化性タンパク質の割合 （DP/TP） の両者に影響されるが，DP/TPがDPに及ぼす影響の程度は，LGCソフトやエルジーシー潤の方がニホンマサリよりも大きいことが明らかになった．いずれの品種も，DP/TPは出穂後0～15 日間の気温と正の相関関係を示したが，LGCソフトとエルジーシー潤では，DP/TPは特に出穂後0～10日間の気温と高い正の相関関係を示し，登熟過程でDP/TPに気温が影響する時期はニホンマサリよりも若干早いことが示唆された．したがって， タンパク質変異米水稲品種のDPを抑制するためには，登熟初期が高温にならないような作期設定が重要と考えられた．DPにはTPも影響し，TPは出穂期の茎葉部窒素含有率・含有量と正の相関関係，登熟歩合と負の相関関係を示した．このことから，出穂期の窒素栄養状態と登熟歩合に留意する作付け計画や栽培管理が重要と考えられた．

Agrobacterium-mediated co-transformation of rice using two selectable marker genes derived from rice genome components

A method for Agrobacterium-mediated co-transformation of rice (Oryza sativa L.) was developed using rice-derived selection markers. Two T-DNAs were efficiently introduced into separate loci using selectable marker gene cassettes consisting of the mutated acetolactate synthase gene (mALS) under the control of the callus-specific promoter (CSP) (CSP:mALS) and the ferredoxin nitrite reductase gene (NiR) under the control of its own promoter (NiR P:NiR). The CSP:mALS gene cassette confers sulfonylurea herbicide resistance to transgenic rice callus. The NiR P:NiR construct complements NiR-deficient mutant cultivars such as 'Koshihikari', which are defective in the regulation of nitrogen metabolism. In the present study, the CaMV35S:GUS and CaMV35S:GFP gene cassettes were co-introduced into the 'Koshihikari' genome using our system. Approximately 5-10 independent transgenic lines expressing both the GUS and GFP reporters were obtained from 100 Agrobacterium co-inoculated calli. Furthermore, transgenic 'Koshihikari' rice lines with reduced content of two major seed allergen proteins, the 33 and 14-16kDa allergens, were generated by this co-transformation system. The present results indicate that the generation of selectable antibiotic resistance marker gene-free transgenic rice is possible using our rice-derived selection marker co-transformation system. Key message An improved rice transformation method was developed based on Agrobacterium-mediated co-transformation using two rice genome-derived selectable marker gene cassettes.

Total Nutrient Uptake by Grain plus Straw and Economic of Fertilizer Use

An experiment was conducted at BINA (Bangladesh Institute of Nuclear Agriculture) substation, Satkhira on slightly calcareous silty clay soil during the boro season of 2009-2010 to investigate the effects of different combinations of inorganic fertilizers in order to achieve sustainable high yield goal in the STL-655 rice mutant cultivar. The six treatment combinations were: T1 (absolute control), T2 (N60 P20 K40 S10 Zn1), T3 (N80 P25 K50 S15 Zn1.5), T4 (N100 P30 K60 S20 Zn2), T5 (N120 P35 K70 S25 Zn3) and T6 (N140 P40 K80 S30 Zn4) that was laid out in a randomized complete block design (RCBD) with three replications having per plot size was 5m x 4m. The results revealed that grain and straw yields of STL-655 rice mutant responded significantly with the different treatment combinations. The highest grain (3.95 t/ha) and straw yield (7.38 t/ha) was obtained in T6 (Soil test basis high yield goal) treatment, which was significantly higher than all other treatments. The treatment T6 (N140 P40 K80 S30 Zn4) caused an increase of 60% grain yield and 27% higher straw yield over the control. Nutrient uptake of N, P, K and S by grain of boro rice (STL-655 rice mutant) varied from 25.14 to 48.02, 5.40 to 8.14, 11.76 to 23.02 and 4.15 to 7.09 kg/ha, respectively. The N, P, K and S uptake by straw of boro rice (STL-655 rice mutant) varied from 20.36 to 35.85, 5.47 to 11.05, 59.01 to 159.6 and 9.54 to 12.97 kg/ha, respectively.DOI: http://dx.doi.org/10.3329/jesnr.v4i2.10139 J. Environ. Sci. & Natural Resources, 4(2): 83-87, 2011

Nutritional value of white lupins (Lupinus albus) for broilers: apparent metabolisable energy, apparent ileal amino acid digestibility and production performance

Two experiments were conducted to evaluate the nutritional value of three cultivars (Promore, Kiev mutant and Ultra) of white lupins (Lupinus albus L.) for broilers. In experiment 1, the apparent metabolisable energy (AME) and ileal amino acid digestibility coefficients of the three cultivars were determined. The cultivar effects were significant (P < 0.05) for AME, but the ileal amino acid digestibility coefficients were similar (P > 0.05) between cultivars. The AME value of Ultra cultivar was lower (P < 0.05) than those of Promore and Kiev mutant cultivars. In Experiment 2, using the AME and ileal digestible amino acid values determined in Experiment 1, diets containing 200 g/kg of lupin were formulated and the effects of feeding these diets on performance, digestive tract development and excreta quality of broiler starters were investigated. Weight gain, feed intake and feed per gain of broilers fed diets containing white lupins were similar (P > 0.05) to those fed the maize–soybean meal diet. The performance of birds fed diets containing different cultivars of white lupins was similar (P > 0.05). Several digestive tract parameters were influenced by the dietary inclusion of white lupins. In particular, the relative liver weight and the relative empty weights of small intestine and caeca in birds fed diets containing white lupins were higher (P < 0.05) than those fed the maize–soybean meal diet. No differences (P > 0.05) were observed in the excreta quality scores between the birds fed the maize–soybean meal diet and those fed diets containing white lupins.

Exophiala sp. LHL08 reprograms Cucumis sativus to higher growth under abiotic stresses

Endophytic fungi are potential sources of secondary metabolites; however, they are little known for phytohormones secretion and amelioration of plant growth under abiotic stresses. We isolated a novel endophyte from the roots of Cucumis sativus and identified it as a strain of Exophiala sp. by sequencing internal transcribed spacer/large subunit rDNA and phylogenetic analysis. Prior to identification, culture filtrate (CF) of Exophiala sp. has shown significant growth promotion of Waito-C [a gibberellins (GAs)-deficient mutant cultivar] and Dongjin-byeo (normal GAs biosynthesis cultivar) rice seedlings. CF analysis of Exophiala sp. showed the presence of physiologically active GAs (GA₁, GA₃, GA₄ and GA₇) and inactive GAs (GA₅, GA₈, GA₉, GA₁₂ and GA₂₀). Exophiala sp. had higher GAs in its CF than wild-type strain of Gibberella fujikuroi except GA₃. Influence of Exophiala sp. was assessed on cucumber plant's growth and endogenous abscisic acid (ABA), salicylic acid (SA) and bioactive GAs under salinity and drought stresses. Exophiala sp.-treated plants have shown significantly higher growth and rescued the host plants from stress promulgated water deficit, osmotic and cellular damage. The altered levels of stress-responsive ABA showed low level of stress confined to endophyte-applied plants than control. Elevated levels of SA and bioactive GAs (GA₃ and GA₄) in endophyte-associated plants suggest stress-modulating response toward salinity and drought. In conclusion, symbiotic relations between Exophiala and cucumber have reprogrammed the host plant growth under abiotic stresses, thus indicating a possible threshold role of endophytic fungi in stress alleviation. This study could be extended for improving agricultural productivity under extreme environmental conditions.

Ethyl-methane-sulfonate(EMS) 처리에 의한 춘란 잎 돌연변이 품종의 개발

본 연구는 돌연변이원인 EMS(ethyl-methane-sulfonate)를 이용하여 춘란 잎 돌연변이 품종을 개발하고자 수행되었다. 조직배양기술을 이용하여 발아시킨 춘란 근경에 0.2%의 EMS를 처리함으로써 엽록소 결핍 돌연변이 근경을 유도하였다. EMS 처리시 50%이상의 춘란 근경이 갈변되었으며, 갈변된 근경을 근경증식용 고체배지에 배양하였을때 갈변된 근경의 일부 조직으로부터 새로운 측지근경의 생장이 관찰되었다. 이러한 근경조직을 절단하여 1년간 계대배양하던 중 관찰된 색소변이 근경을 식물체로 재분화시킨 결과 중투, 사피, 산반, 단엽종 등 다양한 잎 돌연변이 식물체들로 분화하였다. 이러한 결과들로부터 EMS 처리에 의해 잎 돌연변이 식물체들이 효과적으로 유도되었음을 확인할 수 있었다. 또한 본 연구결과에서 얻어진 춘란잎 돌연변이 식물체를 대량 증식시킬 수 있는 배양체계도 확립되어있다. 그러므로 본 연구에서 개발한 잎 돌연변이 춘란은 향후 산업적으로 이용이 가능할 것으로 생각된다. This study was for developing leaf chlorophyll mutant cultivars of Cymbidium goeringii by ethyl-methanesulfonate(EMS) treatment. Chlorophyll mutant rhizomes were easily produced by 0.2% EMS treatment in this genus. Among the mutants, they became dark brown about 50% of the rhizomes. When the dark-brown rhizomes were cultured in a solidified MS medium, new rhizomes were formed from part of the old ones. Chlorophyll mutant rhizomes were obtained from subcultured meristem tissues of newly-formed rhizomes. The rhizomes were cut and subcultured for a year and then became mutant plants. As the results, they produced 4 kinds of leaf mutant cultivars; zigzag-striped, comb-striped, net-striped, and dwarf types, indicating that the EMS treatment in the rhizome could produce versatile leaf chlorophyll regulating mutants. These results suggest that our method is useful for developing leaf mutant cultivars of this planta which they are estimated as higher commercial values.

Gamma irradiation influences on some biological traits in two almond (Prunus amygdalus, L) cultivars

Mutation by ionizing radiations such as gamma-rays is being employed as one of the mutation breeding approaches to obtain the desirable mutant cultivars and genotypes in plants. Almond cultivars 'A200' and 'Sahand' are self-incompatible following pollination and fertilization problems. Therefore, obtaining their late-flowering and self-fertile mutants with good biological traits, by means of mutation, will be very bounteous for breeders and producers. This study was conducted to evaluate the effects of different exposition times to gamma-radiation on some biological traits of two late-blooming cultivars ‘A200’ and ‘Sahand’. Current shoots of 'A200' and 'Sahand' were exposed to 36 µC gamma-radiation for 0, 5, 10, 30 and 150 min from the Cobalt 60. The factorial experiment was carried out on 4-year old irradiated trees based on completely-randomized design (CRD) and some biological traits such as: resistance to diseases agents, partial fungus and pests (aphid, mite, etc.), blooming date, leaf bud break date, bearing type, leaf area (LA) and flower density were investigated in all irradiated plants. Results showed that long exposition times have significant positive effects on resistance to disease agents such as: polystigma occharaceum, mite, LA and flower density, but did not have significant effect on bearing type, resistance to aphids, blooming and leaf bud break dates in spring. Effects of cultivars were significant on resistance to pests (aphid, mite and other main destructive pests) and diseases agents and bearing type, while no significance was seen on blooming, leaf bud break dates, LA and flower density. Interaction effect between cultivars and exposition time was significant on resistance to diseases, mite and flowering date, but was not significant on LA, flower density, resistance to aphid and leaf bud break date. However, the maximum resistance to diseases agents, aphid and mite was observed in plants irradiated 150 min in both cultivars. Key words: Almond, breeding, mutants, gamma-irradiation, biological traits.

Radiosensitivity of sunflower inbred lines to mutagenesis

SUMMARY For much of the past century, mutagenesis has gained popularity in plant genetics research as a means of inducing novel genetic variation. Induced mutations have been applied for the past 40 years to produce mutant cultivars in sunflower by changing plant characteristics that significantly increase plant yield and quality. The present study is focused on generating baseline data to elucidate the role of genotypic differences in the response of sunflower to induced mutagenesis with the aim of expanding the applicability of the use of induced mutant stocks in the genetic improvement of the crop and in its functional genomics. The strategy adopted was to estimate the optimal treatment conditions (doses of mutagens) through relating the extent of damage in seedling progeny to the exposure levels of the initiating propagates to mutagens. Seeds of fifteen elite sunflower genotypes of commonly used as breeding stocks and grown on commercial scales were treated with a range of mutagens: gamma rays (γ rays); fast neutrons and with ethyl-methane-sulphonate (EMS) at different treatment doses. The three mutagenic agents affected seedling height, reducing it with increasing dosage. Based on the mutagen damage on seedling height, the 50% and 30% damage indices (D 50 and D 30 , respectively) were estimated for the 15 sunflower genotypes for the three mutagens. The D 50 (D 30 ) values for the sunflower lines ranged from 120 to 325 Gy (5 to 207 Gy) for gamma irradiation; 9 to 21 Gy (0.1 to 10 Gy) for fast neutrons and 0.69 to 1.55% (0.01 to 0.68%) concentration of EMS.

Isolation and identification of oryzamutaic acids A and D from an Oryza sativa spontaneous mutant with yellow endosperm

Oryzamutaic acids A and D, alkaloids with a novel type of nitrogen-containing heterocyclic ring system, which had previously been isolated only from the brown rice (husked rice) of Hatsuyamabuki, an Oryza sativa artificial mutant cultivar with yellow endosperm, were isolated from the brown rice of Musashino 20, an Oryza sativa spontaneous mutant line with yellow endosperm. The concentrations of oryzamutaic acids A and D in the brown rice of Musashino 20 were similar to those of Hatsuyamabuki, respectively. These results suggest that oryzamutaic acid A may play an important role in the yellow color of the brown rice of Musashino 20.

Plant mutation breeding in agriculture.

Abstract A mutation is a sudden heritable change in the DNA in a living cell, not caused by genetic segregation or genetic recombination. Mutation breeding is the purposeful application of mutations in plant breeding. Unlike hybridization and selection, mutation breeding has the advantage of improving a defect in an otherwise elite cultivar, without losing its agronomic and quality characteristics. Mutation breeding is the only straightforward alternative for improving seedless crops. Since the first release of mutant cultivars that resulted from basic mutation research in Europe, mutation breeding has found a niche in plant breeding because of these advantages. Methodologies for mutation induction have been improved in main crops for both physical and chemical mutagens, and selection methodologies for mutant populations have been described. New mutagenic agents such as ion-beam radiation and cosmic rays are being investigated and a hitherto undescribed wide spectrum of mutations has been observed. Nevertheless, alkylating agents and ionizing radiation are still popular. The development of robust in vitro techniques for many crop species has contributed to improving the efficiency of mutation breeding. The ability to handle large mutagenized populations in a confined space, faster progeny turnover in vegetatively propagated species and the ability to screen for several biotic and abiotic stress factors in the culture environment make in vitro approaches very efficient. Mutant screening has undergone revolutionary changes in the past decade with reverse genetic approaches taking precedence. Therefore, integration of mutation techniques with molecular approaches is providing exciting opportunities for modern plant breeding.

Analysis of Storage Protein Distribution in Rice Grain of Seed-Protein Mutant Cultivars by Immunofluorescence Microscopy

Localization of storage proteins in rice grains of seed-protein mutant cultivars, low-glutelin cultivars LGC-1, LGCsoft and a 26-kDa-globulin-deficient low-glutelin cultivar LGC-Katsu, was examined by immunofluorescence microscopy using fluorescence-labeled antibodies of 13 kDa prolamin and 23 kDa glutelin. Abundant 13 kDa prolamin and 23 kDa glutelin was observed in the outer regions of rice grains. Image analysis revealed that peaks of fluorescence intensity of both proteins were located at 2–7% of the width or longitudinal length of brown rice distant from the outer surface of brown rice (RDOS) on the dorsal, ventral, and apical sides of brown rice. In these seed-protein mutant cultivars and a normal-type cultivar Nihonmasari, the foot of the distribution peaks of both proteins were located at 20–30% RDOS on the ventral and apical side. In contrast, on the dorsal side of rice grain, varietal differences of RDOS at the foot of the distribution peak of both proteins varied with the cultivar. The RDOS was 20 –40%; and Nihonmasari >LGC-1≒LGCsoft >LGC-Katsu. Although the quantity of 13 kDa prolamin and 23 kDa glutelin greatly varied with the cultivar in the outer region of rice grain, both proteins were distributed uniformly at low levels in the inner region in all cultivars. Furthermore, SDS-PAGE analysis showed that a larger quantity of 13 kDa prolamin localized on the ventral than the dorsal side of rice grains in seed-protein mutant cultivars, especially in LGC-Katsu.

Identification of Vegetatively Propagated Turf Bermudagrass Cultivars Using Simple Sequence Repeat Markers

ABSTRACTAccurate identification of bermudagrass (Cynodon spp.) cultivars is necessary to ensure the purity of the cultivars produced by sod farmers, to protect the intellectual property of cultivar developers, and to assure cultivar purity for the benefit of turfgrass consumers. Vegetatively propagated turf bermudagrass cultivars have been extensively used in the turf industry not only in the USA but also in many other countries. Accordingly, the objectives of the study were to examine simple sequence repeat (SSR) markers for their ability to distinguish commonly grown clonal turf bermudagrass cultivars, which were derived through crosses and mutations, from each other and their respective parent cultivars and to develop a set of SSR markers for accurate identification of commercially used clonal cultivars. Thirty‐two clonal turf bermudagrass genotypes comprising 29 commercially released cultivars and 3 Oklahoma State University experimental lines were assessed by 11 microsatellite markers. A total of 141 DNA fragments were generated for the 11 primer pairs in the 32 bermudagrass genotypes, with an average of 12.8 bands per primer pair. Forty‐four fragments were cultivar specific. The SSR markers successfully identified 22 cultivars when mutant cultivars had the same banding patterns as the 2 parent cultivars, ‘Tifgreen’ and ‘Tifway’. It was concluded from the study that the SSR markers are highly polymorphic and can be utilized as a reliable tool for accurate cultivar identification in nonmutated bermudagrass.

Specific starch digestion of maize alpha‐limit dextrins by recombinant mucosal glucosidase enzymes

Starch digestion requires two luminal enzymes, salivary and pancreatic alpha‐amylase (AMY), and four small intestinal mucosal enzyme activities from the N‐ and C‐terminals of maltase‐glucoamylase (MGAM) and sucrose‐isomaltase (SI) complexes. AMY is not a requirement for starch digestion to glucose but dramatically amplifies α‐glucogenesis by producing α‐limit dextrins (LDx) as favored substrates for the mucosal enzymes.Aimto study substrate specificity of α‐glucogenesis by four recombinant MGAM and SI subunits.MethodsRecombinant α‐glucosidase domains were produced in drosophila (N‐) or baculovirus (C‐) cell lines and purified by histags. LDx was produced with AMY from normal maize and three mutant cultivars with different amylopectin structures: normal, waxy, ae waxy and du waxy. Glucose released in vitro was measured by GOPOD.ResultsN‐MGAM subunit releases glucose from shortest linear oligomers while the other three subunits digest longer chains or branched molecules.ConclusionsThis is the first time that the individual α‐glucogenic activities of all four mucosal enzyme subunits have been tested. The individual α‐glucosidase subunits had different activities for each cultivar LDx substrate and selective affinities for LDx from different cultivars. Combinations of α‐glucosidase subunits thus provide a broader spectrum of α‐glucogenic activities from structurally varied starch LDx.

Optimizing TILLING and Ecotilling techniques for potato (Solanum tuberosum L)

BackgroundThe TILLING and Ecotilling techniques for the discovery of nucleotide polymorphisms were applied to three potato (Solanum tuberosum) cultivars treated with gamma irradiation. The three mutant cultivars tested were previously shown to exhibit salinity tolerance, an important trait in countries like Syria where increasing soil salinity is affecting agricultural production.FindingsThree gene-specific primer pairs were designed from BAC sequence to amplify ~1 to 1.5 kb of gene target. One of the three primer pairs amplified a single gene target. We used this primer pair to optimize enzymatic mismatch cleavage and fluorescence DNA detection for polymorphism discovery. We identified 15 putative nucleotide polymorphisms per kilobase. Nine discovered polymorphisms were unique to one of the three tetraploid cultivars tested.ConclusionThis work shows the utility of enzymatic mismatch cleavage for TILLING and Ecotilling in different varieties of potato. The method allows for rapid germplasm characterization without the cost and high informatics load of DNA sequencing. It is also suitable for mutation discovery in high-throughput reverse genetic screens.

A PCR-based diagnostic tool for distinguishing grape skin color mutants

Berry skin color mutants are phenotypically different from their original cultivars, but they show identical molecular profile if analysed by using microsatellite markers. This work gives an easy, inexpensive and quick diagnostic tool to discriminate these somatic variants. We distinguished some grape ( Vitis vinifera L.) skin color mutants from white to red or pink and from black to grey, pink or white and we investigated their molecular bases by single-strand conformational polymorphism (SSCP), single base primer extension and coding sequence analysis of anthocyanin biosynthetic enzyme genes and by polymerase chain reaction (PCR) analysis of VvmybA1 regulatory gene. Analyses of structural genes did not reveal polymorphisms between wild type and mutant cultivars but only among different varieties, whereas the study of VvmybA1 regulatory gene has given important outcomes for color mutants characterisation. The discrimination between white wild type and its derived colored mutant and between black wild type and white mutant has been obtained through a simple test of amplification for presence/absence. The discrimination between black wild type and less colored mutant has occurred through a quantitative result on agarose gel confirmed by real-time PCR analysis: the amount of functional allele in less colored somatic variants genome was about one-fourth of the correspondent quantity in original black cultivars genome.

Food chemical properties of low-phytate rice cultivar, Sang-gol

Phytic acid inhibits mineral absorption in the intestines of monogastric animals, inhibition which can contribute to public health problems in human populations. This research compared the nutritional properties of parent rice cultivar Il-pum with those of an Il-pum-derived, mutant low-phytate rice cultivar, Sang-gol. No significant differences were shown in moisture, fat, carbohydrate and mineral content between Il-pum and Sang-gol. In the composition of protein and fatty acid, there were also no differences between the two cultivars. In the nutritional aspects, though Sang-gol had a 50% lower phytate content than Il-pum, the total phosphorus contents in the two cultivars were shown to be similar. These results indicated that Sang-gol had similar nutritional properties to those of the parent cultivar Il-pum, with the added benefit of lower phytate content.

Analysis of Bud Sport Cultivars of Peach (Prunus persica (L.) Batsch) by Simple Sequence Repeats (SSR) and Restriction Landmark Genomic Scanning (RLGS)

To detect genetic mutations in bud sport cultivars of peach, RLGS (restriction landmark genomic scanning) analysis was performed on 7 putative bud sport mutant cultivars after SSR (simple sequence repeats) analysis for identifying false-mutants. Three cultivars, ‘Yawata Hakuho’, ‘Odoroki’, and ‘Kanoiwa Hakuto’, postulated to be bud sport mutants, were confirmed as false-mutant cultivars. This suggests that other false-mutant strains of peach are also likely to be registered with the Plant Variety Authority as bud mutant cultivars. A stable RLGS profile of peach, obtained using NotI as a landmark enzyme, showed about 400 spots in a single experiment. Comparing the profiles between mutant and original cultivars, polymorphic spots were discovered in 2 mutatnt cultivars, ‘Gyosei’ and ‘Nagasawa Hakuho’, but were not detected by SSR analysis. RLGS was thus considered to be an effective method to detect very small genomic variations in mutant strains.