Scielo RSS <![CDATA[Crop Breeding and Applied Biotechnology]]> vol. 17 num. 3 lang. en <![CDATA[SciELO Logo]]> <![CDATA[Micropropagation of <em>Cyrtopodium paludicolum</em> (Orchidaceae) from root tip explants]]> Abstract An efficient protocol for in vitro plant propagation of Cyrtopodium paludicolum has been developed using root tips dissected from well-developed seedlings. Root tips were cultured on Knudson medium supplemented with α-naphthaleneacetic acid (NAA), and/or thidiazuron (TDZ). TDZ did not induce protocorm-like bodies (PLBs) in the NAA absence, indicating phytoregulators synergistic effect. Medium supplemented with 1.34 μM NAA and 2.27 μM TDZ resulted in better response on PBLs, and subsequent shoot differentiation (55.25 shoots per explant), and in better rooting number and root length responses, favoring acclimatization with 90% of survived plants. However, the medium supplemented with only NAA (1.34 μM) resulted in 33.50 shoots per explant. Histological sections confirmed that only one PLB was induced per responsive root tip, and it showed numerous dispersed and extended meristemoids, or division centers that originated new PBLs. Additionally, this protocol could be an excellent model to study molecular aspects of root to shoot conversion. <![CDATA[Phenotypic characterization of papaya genotypes to determine powdery mildew resistance]]> Abstract In support of breeding of papaya (Carica papaya), the disease incidence and severity of powdery mildew (Ovulariopsis caricicola) were evaluated in papaya genotypes. Two experiments in complete randomized blocks were carried out, one in the field and the other in a greenhouse. In field experiments, the lowest mean disease incidence was observed on the genotypes ‘Costa Rica’ and ‘Baixinho Super’, and the lowest mean disease severity on ‘Caliman M5’, ‘GTF’, ‘SH 11-08’, and ‘JS 11’. In the greenhouse experiment, the genotypes ‘Caliman M5’, ‘Golden’, ‘Kapoho Solo’, ‘Waimanalo’, ‘Mamão Bené’, ‘SH 12-07’, ‘JS 12’, and ‘GTF’ had the lowest mean incidence in at least one evaluation. On the other hand, for severity, the genotypes ‘Diva’, ‘Sunrise Solo 72/12’, ‘Kapoho Solo PA’, ‘Waimanalo’, ‘Maradol’, ‘Maradol GL’, ‘SH 15-04’, ‘FMV, ‘JS 12-4’, ‘SH 12-07’ and ‘Sekati FLM’ had the lowest means. These results indicate these genotypes for a possible use in breeding for reduction of powdery mildew intensity. <![CDATA[Evaluation of different selection indices combining Pilodyn penetration and growth performance in <em>Eucalyptus</em> clones]]> Abstract The present study aimed to evaluate the selection indices efficiency for Pilodyn penetration combined with growth traits in Eucalyptus clones. It was carried out experiments in a randomized block design, with single tree plots and 30 replications. Diameter at breast height (DBH), total height (TH), and Pilodyn penetration as an indicator of basic density (BD) were measured. The volume was estimated. Based on predicted genotypic values, three indices presented the highest accuracies: I8 (based on partial correlation), I7 (based on the concept of multivariate BLUP) and I3 (based on two variables as ratio, which uses a third heritability estimate associated to the ratio DBH/BD, besides the two heritabilities of DBH and BD). Thus, it is possible to optimize the selection by combining properly the variables using their genetic control, precision and the relationships between them. The best options came from using only two no redundant traits DBH and BD. <![CDATA[Parents choice and genetic divergence between cambuci fruit tree accessions]]> Abstract Fifty-eight cambuci fruit accessions were collected and propagated by seeds. Forty fruits of each accession were collected and evaluated for longitudinal and transverse diameter, fruit weight, number of seeds, seeds weight, total soluble solids, % citric acid, ratio, pH, firmness, vitamin C, and color. The phenotypic correlation between the characters and the relative contribution of the characters for the divergence among accessions were estimated and quantified by the Euclidean genetic distance, and cluster analysis was carried out according to the Neighbour Joining Tree. The significant correlations between the variables allowed the use of indirect selection as an auxiliary tool in the process of domestication and breeding of this species. Weight of 1000 seeds presented the greatest variation and contributed the most with genetic diversity. The expansion of the variability and the association of characters of interest can be promoted by the hybridization of the most divergent accessions, 14 and 43. <![CDATA[Evaluation of total flavonoid content and analysis of related EST-SSR in Chinese peanut germplasm]]> Abstract As important antioxidants and secondary metabolites in peanut seeds, flavonoids have great nutritive value. In this study, total flavonoid contents (TFC) were determined in seeds of 57 peanut accessions from the province of Hebei, China. A variation of 0.39 to 4.53 mg RT g-1 FW was found, and eight germplasm samples containing more than 3.5 mg RT g-1 FW. The TFC of seed embryos ranged from 0.14 to 0.77mg RT g-1 FW. With a view to breeding high-quality peanut varieties with high yields and high TFC, we analyzed the correlations between TFC and plant and pod characteristics. The results of correlation analysis indicated that TFC was significantly negatively correlated with pod number per plant (P/P) and soluble protein content (SPC). We used 251 pairs of expressed sequence tag - simple sequence repeat (EST-SSRs) primers to sequence all germplasm samples and found four EST-SSR markers that were significantly related to TFC. <![CDATA[Gene transfer utilizing pollen-tubes of <em>Albuca nelsonii</em> and <em>Tulbaghia violacea</em>]]> Abstract Developing a tissue culture-independent genetic transformation system would be an interesting technique for gene transfer in valuable medicinal and horticultural plants. Efficient gene delivery (Agrobacterium tumefaciens strain LBA 4404: harbouring PBI121 plasmid) was achieved with Km-resistant pollen grains (pollen tube technique) and were found to be GUS-positive for Albuca nelsonii (31.3%) and Tulbaghia violacea (32.6%). The Km-resistance (95.6% for A. nelsonii and 86.7% for T. violacea) and GUS-positive (100% for A. nelsonii and 97.5% for T. violacea) putative transgenic seedlings in vitro were obtained with 200 mg L-1 Km. The in vitro plants were obtained from leaf explants of putative transgenic seedlings and were confirmed to be Km-resistant and GUS-positive (T. violacea, 73.7% and A. nelsonii, 80.5%). The plants were successfully acclimatized in the greenhouse. We describe a tissue culture-independent gene transfer technique with high efficiency clonal transgenic plant production for A. nelsonii and T. violacea. This can also be applied to biotechnological crop improvement of the same species and potentially to other plants. <![CDATA[Oleic acid variation and marker-assisted detection of Pervenets mutation in high- and low-oleic sunflower cross]]> Abstract High-oleic sunflower oil is in high demand on the market due to its heart-healthy properties and richness in monounsaturated fatty acids that makes it more stable in processing than standard sunflower oil. Consequently, one of sunflower breeder’s tasks is to develop stable high-oleic sunflower genotypes that will produce high quality oil. We analyzed variability and inheritance of oleic acid content (OAC) in sunflower, developed at the Institute of Field and Vegetable Crops, by analyzing F1 and F2 progeny obtained by crossing a standard linoleic and high-oleic inbred line. F2 individuals were classified in two groups: low-oleic with OAC of 15.24-31.28% and high-oleic with OAC of 62.49-93.82%. Monogenic dominant inheritance was observed. Additionally, several molecular markers were tested for the use in marker-assisted selection in order to shorten the period of detecting high-oleic genotypes. Marker F4-R1 was proven to be the most efficient in detection of genotypes with Pervenets (high-oleic acid) mutation. <![CDATA[Introgression of the Rl <sub>adg</sub> allele of resistance to potato leafroll virus in <em>Solanum tuberosum</em> L.]]> Abstract Genetic resistance to Potato Leafroll Virus (PLRV) is polygenic, which hinders the obtainment of resistant cultivars. However, works carried out at the International Potato Center have identified an andigena accession, LOP-868, with high resistance level and low accumulation of PLRV due to the gene of major effect Rladg. We verify the transfer of the Rladg allele to clones of the cross between LOP-868 and UFLA clones, by using the SCAR RGASC850 molecular marker; to evaluate the reaction of these clones to PLRV by inoculating the virus using aphids; and to analyze their agronomic performance of clones. Among the clones inoculated with viruliferous aphids, 49.3% were negative to the serological test, indicating possible resistance. Clones containing the Rladg allele were identified by the RGASC850 molecular marker, which demonstrates the possibility of transferring the Rladg allele of resistance to PLRV from LOP-868 to Solanum tuberosum. Some clones that presented the Rladg allele are also promising for agronomic performance. <![CDATA[A multiplex PCR system for detection of wide compatibility allele <em>S5-n</em> and erect panicle allele <em>dep1</em> in rice]]> Abstract Wide compatibility and erect panicles are important traits for heterosis and ideal plant type breeding in rice and accordingly are targets for rice yield improvement. In this study, a multiplex PCR system based on functional markers was developed to simultaneously identify genotypes of the wide compatibility allele S5-n and the erect panicle allele dep1. Forty-nine rice varieties in the Huang-Huai-Hai region of China were identified using this system. Thirty-three varieties contained the erect panicle allele dep1 and two varieties contained the wide compatibility allele S5-n. The frequency of dep1 was obviously higher than that of S5-n. The multiplex PCR method was also tested using an F2 segregating population and was found to be simple, efficient, and reliable. It will be useful in marker-assisted selection based on the wide compatibility allele S5-n and erect panicle allele dep1 to breed super rice varieties using indica and japonica heterosis. <![CDATA[Diallel analysis in agronomic traits of Jatropha]]> Abstract The objectives of this study were to estimate the general and specific combining ability of the parents, and to verify the existence of maternal effect and inbreeding depression in Jatropha. The experiment was carried out from 2010 to 2015, in the municipality of Planaltina, Distrito Federal. The following traits were evaluated: plant height, stem diameter, canopy projection between the row, canopy projection on the row, number of branches, mass of one hundred grains, and grain yield. Cytoplasmic effects and effects of female parent nuclear genes were observed for all traits. Dominance effects were predominant in the genetic control of all traits. Genotypes 107 and 190 were the superior parents for the reduction of the size, and for the increase of grain yield. No inbreeding depression was observed for grain yield. The most promising crosses for the conduction of segregating populations and increment in grain yield were 190x107, 107x190 and 259x107. <![CDATA[Recurrent selection of popcorn composites <em>UEM-CO1</em> AND <em>UEM-CO2</em> based on selection indices]]> ABSTRACT Selection indices were applied to data sets of 169 half-sib families of the popcorn composites UEM-Co1 and UEM-Co2 in four cycles of recurrent selection. From 2005 to 2008, the experiments were arranged in a 13 by 13 lattice square design, with two replications per cycle and composite. Genetic gains for popping expansion (PE) and grain yield (GY) were estimated based on several selection indices and truncation selection. The magnitude and balance of gains estimated for each trait by the indices were compared by an auxiliary statistical value (Ci). This value Ci consists of an arbitrary value, resulting from differences between the gains estimated for n traits by truncation selection and by index i. The indices of Subandi and Mulamba and Mock were the most promising to estimate high and balanced genetic gains for PE and GY in recurrent selection of half-sib popcorn families. <![CDATA[<em>Passiflora cristalina</em> and <em>Passiflora miniata</em>: meiotic characterization of two wild species for use in breeding]]> Abstract Passiflora cristalina and Passiflora miniata are two new wild species found in the southern Amazon region. This study aimed to analyze the meiotic behavior of the two species, by meiotic analysis, meiotic index and pollen grain viability, using routine methodologies of the laboratory. By the meiotic analysis, the two species were diploid with 18 chromosomes, and nine bivalents were observed in diakinesis. Laggard chromosomes and fiber spindle problems were the abnormalities observed in both species. The recombination indices were 21.6 and 18.8 for P. cristalina and P. miniata, respectively. The most common abnormal post-meiotic products were triads. The meiotic index and the pollen grain viability for P. cristalina were 90.6% and 98.9%, respectively, and 91.6% and 82.2% for P. miniata, respectively. Based on the results, both species are fertile. Thus, gene transference to sour passion fruit by interspecific hybridization is possible in breeding programs. <![CDATA[MS INTA 416: A new Argentinean wheat cultivar carrying Fhb1 and Lr47 resistance genes]]> Abstract MS INTA 416 is a hard red winter wheat selected for high yield potential and good bread-making quality, combined with moderate resistance to Fusarium-head-blight and high resistance to leaf-rust, due mainly to presence of resistance genes Fhb1 and Lr47. MS INTA 416 is adapted to main production areas of Central-Argentina. <![CDATA[MG Travessia: a coffee arabica cultivar productive and responsive to pruning]]> Abstract This paper presents the results of progeny 1190-1170-2, which was recorded as ‘MGS Travessia’ and selected based on its performance in the state of Minas Gerais. The cultivar has short size, cylindrical canopy, high yield capacity, high vegetative vigor, very satisfactory husk/bean ratio, grain quality compatible to traditional cultivars, and is very responsive to skeleton pruning. <![CDATA[SCS122 Miura - New Rice Cultivar]]> Abstract The rice cultivar SCS122 Miura has modern architecture, lodging resistance, late maturity cycle, moderate resistance to blast, high yield potential, long grains and adequate cooking quality. Industrial tests have demonstrated that the grains are suitable for parboiled rice. SCS122 Miura is recommended for all rice-producer regions of the state of Santa Catarina, Brazil. <![CDATA[IAC OL 5 - New high oleic runner peanut cultivar]]> Abstract IAC OL 5 is a new peanut cultivar recommended to growers of peanut regions of the state of São Paulo as another option for planting during the intervals of sugarcane renewal. Its main traits are its runner growing habit, its moderate resistance to virus and foliar diseases, and the high oleic trait.