Francisco José Becker Reifschneider

Search for sources of early blight (Alternaria solani) field resistance not associated with vegetative late maturity in tetraploid potato germplasm

SummaryA total of 934 potato cultivars and clones from different breeding programmes across the world were tested for their reaction to early blight (Alternaria solani) in Brasilia-DF, Brazil. This field trial was set up in order to identify tetraploid potato genotypes with useful levels of resistance to early blight (EB) that were not correlated with late maturity or lateness. Artificial inoculation (spread ofA. solani infected leaves over plant canopy) was employed even though EB occurs naturally at epidemic levels in the test area. Four disease assessments were made every 10 days, beginning 45 days after planting. Based on the evaluation made 65 days after planting, only 27 clones were identified that had less lesioned leaf area than the resistant standard (cv. Aracy). Area under disease progress curve (AUDPC) was also used as a criterion of resistance. Using AUDPC as a parameter, 22 genotypes were identified presenting values lower than or identical to cv. Aracy. Differences in the commercial yield were recorded in genotypes with identical response to EB, suggesting that distinct levels of tolerance to EB also exist. In spite of the strong correlation between EB resistance and late maturity, some genotypes derived from the parental materials ‘NDD 277-2’, ‘Kufri Jyoti’, ‘CIP 377888-7’, ‘Maine-28’, and the clones ‘CFS 69.1’ and ‘I-853’ were identified as having good levels of EB field resistance not linked with the negative phenotypic trait of lateness. These materials presented medium to medium-early maturity with a vegetative cycle of around 90–95 days. Some selected genotypes presented more acceptable agronomic characteristics including resistance toPhytophthora infestans, potato leaf roll luteovirus (PLRV) and potato virus Y (PVY). The EB resistance sources identified in this work can be recommended as parental materials for widening the genetic base for EB disease resistance in breeding programmes for highland tropical and subtropical areas.

Effects of 2n-pollen formation by first meiotic division restitution with and without crossover on eight quantitative traits in 4x-2x potato progenies

Abstract The 2n-pollen grains formed by first-division restitution without crossover (FDR-NCO) are unique breeding tools, since they can transmit almost 100% of non-additive genetic effects from the parent to the progeny. FDR-NCO gametes are considered superior to those formed by FDR with crossing over (FDR-CO), which can pass on to the progenies approximately 80% of the heterozygosity and a large fraction of the epistasis. However, 2n-pollen formation by FDR-NCO mechanism requires the incorporation (in homozygous condition) of at least two recessive alleles. In the present work, 40 tetraploid families derived from complete 4x-2x factorial crosses were evaluated under short-day conditions to verify whether or not the postulated genetic superiority of FDR-NCO over FDR-CO gametes holds true for eight quantitative traits in potato. Families were derived from crosses between four 4x commercial cultivars, and a random sample of ten diploid Solanum phureja-haploid S. tuberosum hybrids producing 2n-pollen by either FDR-CO or FDR-NCO. The results indicated no significant superiority of FDR-NCO over FDR-CO families for total tuber yield (TTY) and six other traits (haulm maturity – HM; plant vigor – PV; plant uniformity – PU; eye depth – ED; number of tubers per hill – NTH; and commercial over total yield index – CTI). Based upon cytological observations, the FDR-CO and FDR-NCO gametes are expected to be genetically equivalent for all loci between the centromeres and the chromosomal site of maximum recombination. In our experiment, differences between FDR-CO- and FDR-NCO-derived progenies were not observed for TTY. Therefore, our results can be interpreted as additional evidence for the hypothesis that genes with major effect on TTY expression might have a physical location between centromeres and proximal crossovers in the potato chromosomes. In addition, a similar trend was observed for HM, PV, and ED but apparently not for commercial yield – CY (i.e., tubers with more than 33 mm in diameter).

Genetic resources: the basis for sustainable and competitive plant breeding

Plant genetic resources are the fuel for breeding, which in the search for higher yield and adapted genotypes, manipulates genes in order to meet the needs of farmers, and especially, of the current market. However, the use of accessions available in germplasm banks is low. Topics discussed in this paper emphasize the importance of plant genetic resources, and warn about problems related to genetic vulnerability; also, they discuss about aspects of costs involved in conservation and suggest recommendations for strengthening the area in Brazil.

Cultural and morphological variability of Kabatiella zeae

Twenty-eight isolates of Kabatiella zeae from five countries were used to study variability of the species. A comparison was made of the size of in vivo produced conidia, cultural characteristics, in vitro radial growth rates on different media and temperatures, and minimum time for symptom expression. Isolates were found to differ significantly in size of conidia (length/width ratios of 7.1–10.0) and radial growth rates (1.1–4.4 mm/day on malt agar, at 24°C). Highly significant effects due to temperature, isolate, and temperatureisolate interaction were detected. Growth rates in vitro were not related to time required for symptom development.

Atributos de hortaliças sob a ótica de consumidores: estudo de caso do pimentão no Distrito Federal

Capsicum (chili and bell peppers) breeders at Embrapa Vegetables are focusing project activities to satisfy the demands of both growers and final consumers in order to increase the chances of success in, long-term development of new cultivars. So, a prospection study on consumer demands and perception on bell peppers was started in 2007 in order to identify the main attributes taken in consideration during the act of purchase. This work was divided in two parts: a pilot study with 444 consumers at one supermarket and a survey with 500 consumers of fresh bell pepper, carried out by interviews at five supermarkets in Brasilia, Brazil, which represent distinct income segments. Data were analyzed by categorical data analysis using SAS (Procedure CATMOD) to rank the attributes in order of importance; to contrast the attribute means; and to verify the psychosocial influence on ranking the attributes during the purchase act. In addition, correspondence analysis was used for graphical representation of the attributes separated by the level of importance. During purchase, consumers prioritize the attributes related to the visual aspect (appearance) and firmness of the fruits. Also, differences of perception by gender, age, educational level, marital status and supermarket location were detected. Based on the collected evidence, elderly people are more concerned about nutritional value. Plant breeding programs can be better focused utilizing inputs from similar studies.

Performance measurement in a global program: motivation, new concepts and early lessons from a new system

In 2004, the Consultative Group on International Agricultural Research (CGIAR) established a new performance measurement system. This paper describes the conceptual framework, objectives and principles used in designing the system, and analyzes the impact and lessons learnt. The CGIAR performance management system is innovative for global programs, measuring three dimensions of performance: results, potential to perform and stakeholder perceptions. It is critical that such a global program is flexible as it caters for changing global needs and priorities, adjusts to changing stakeholder profiles, and refines an evolving structure of the program governance. It can be used as a reference for other global programs in the establishment of indicator-based assessment tools. Through diffusion across similar organizations and through pressure by funders the CGIAR system is likely to have a positive impact on the accountability of global programs. Copyright , Beech Tree Publishing.

Novel approaches to extraction methods in recovery of capsaicin from habanero pepper (CNPH 15.192)

Introduction: The objective of this study was to compare three capsaicin extraction methods: Shoxlet, Ultrasound-assisted Extraction (UAE), and Shaker-assisted Extraction (SAE) from Habanero pepper, CNPH 15.192. Materials and Methods: The different parameters evaluated were alcohol degree, time extraction, and solid–solvent ratio using response surface methodology (RSM). Results: The three parameters found significant (p < 0.05) were for UAE and solvent concentration and extraction time for SAE. The optimum conditions for the capsaicin UAE and SAE were similar 95% alcohol degree, 30 minutes and solid–liquid ratio 2 mg/mL. The Soxhlet increased the extraction in 10–25%; however, long extraction times (45 minutes) degraded 2% capsaicin. Conclusion: The extraction of capsaicin was influenced by extraction method and by the operating conditions chosen. The optimized conditions provided savings of time, solvent, and herbal material. Prudent choice of the extraction method is essential to ensure optimal yield of extract, thereby making the study relevant and the knowledge gained useful for further exploitation and application of this resource. Abbreviations used: Nomenclature UAE: Ultrasound-assisted Extraction; SAE: Shaker-assisted Extraction.

Obtenção e Caracterização Morfoagronômica de Linhagens de Pimenta do Tipo Jalapeño Amarelo

Este trabalho foi desenvolvido na Embrapa Hortalicas, com objetivo de caracterizar morfoagronomicamente linhagens de pimenta do tipo Jalapeno Amarelo, atividade essencial para o desenvolvimento de cultivares. Primeiramente foram identificadas tres plantas segregantes da cultivar comercial do tipo Jalapeno Vermelho, que apresentaram frutos de coloracao amarela.

Chapter 109 – Varietal Differences in the Volatile Profile of Bananas with Resistance to Black Leaf Streak Disease

In Brazil, black leaf streak disease, also known as black Sigatoka, is devastating to traditional banana cultivars. Government research institutes are developing new resistant varieties, but if the sensory properties are not taken into account, the breeding program may not succeed. The objective of this work was to compare, by principal component analysis (PCA), the volatile profile (GC-MS) of the most popular banana cultivars in Brazil (Prata and Pacovan), susceptible to black Sigatoka, with nine resistant hybrids. Results showed that Galil 18 and Pacovan Ken were similar to traditional cultivars. Japira presented the richest volatile profile. These cultivars have great potential to replace fruits that are susceptible to banana diseases.

Aroma-Active Compounds of Capsicum Chinense Var. Biquinho

Capsicum chinense var. Biquinho presents a strong aroma without the burning pepper sensation. Headspace volatile compounds were isolated by SPME and analyzed by GC-FID, GC-MS, and GC-O. The major compounds profile showed similarity to the profile of spicier peppers, but several minor compounds presented high importance to Biquinho’s characteristic flavor. Aromagram showed 72 compounds; where α-cardinol, heptylisopentanoate, p-xylene, isohexanol, hexyl butanoate, and (Z)-3-hexenyl pentanoate may be potential markers for the sweet and mild pepper flavor of Biquinho. In future, genetic materials of other chili peppers may have crosses with this pepper, which will improve their sensory characteristics.