Molecular characterization of arabica and Conilon coffee plants genotypes by SSR and ISSR markers

The molecular characterization of ten genotypes of the Coffea arabica plants and of seven genotypes of C. canephora having interesting features for coffee breeding programs was carried to select the parents for breeding. A total of 40 SSR and 29 ISSR primers were used. The primers generated a total of 331 (307 polymorphic and 24 monomorphic) bands. Analysis of genetic diversity presented dissimilarity intervals ranging from 0.22 to 0.44 between the Conilon genotypes, from 0.02 to 0.28 between the Arabica genotypes, and from 0.49 to 0.60 between the genotypes of the two species in the joint analysis. Four groups were formed: I = genotypes of C. arabica, II = four progenies of C. canephora, Conilon group, and one non defined C. canephora (Conilon or Robusta), III = one progeny of un-defined C. canephora (Conilon or Robusta) and IV = one progeny of C. canephora of Robusta group. The grouping formed was consistent with the origins of each group. High stabilities of the bifurcations were found by bootstrap analysis. The use of molecular markers of the SSR and ISSR types in the diversity study was efficient in distinguishing genotypes between and within C. arabica and C. canephora. .

Cryostorage of sunflower seeds / Crioarmazenamento de sementes de girassol

Sunflower seeds present a great economic importance due to the high oil content. The aim of this study to evaluate the effect of storage sub-zero temperatures and the quick and slow thawing methods on the physiologic quality of seeds of Helianthus annuus, cultivars BRS 122 and BRS 324. The experiment was set up in a randomized complete design, in a factorial 2x6 (cultivars x procedures) with four replications; means were compared by the Tukey test at 5%. Were evaluated: first count and percentage of germination, mean time of germination, germination speed index, dry mass seedling, root and shoot length and stability of membranes, through electrical conductivity test solution soaking of seed. Sunflower seeds tolerate storage in sub zero temperatures up to six months; the seeds of cultivars BRS and BRS 324 122 present different answers in relation to the type of freezing and thawing.

As sementes de girassol apresentam grande importância econômica devido ao grande conteúdo de óleo. Objetivou-se neste trabalho avaliar o efeito do armazenamento em temperaturas sub-zero e os métodos de descongelamento rápido e lento sob a qualidade fisiológica de sementes de Helianthus annuus cultivares BRS 122 e BRS 324. Utilizou-se o delineamento experimental inteiramente casualizado, num fatorial 2x6 (cultivares x procedimentos), com quatro repetições; as médias foram comparadas pelo teste de Tukey em nível de 5%. Foram avaliados: primeira contagem e porcentagem de germinação, tempo médio de germinação, índice de velocidade de germinação, massa seca de plântulas, comprimento de raiz e parte aérea e estabilidade das membranas, através de teste de condutividade elétrica da solução de embebição das sementes. As sementes de girassol toleram o armazenamento em temperaturas sub-zero até seis meses; as sementes dos cultivares BRS 122 e BRS 324 apresentam respostas diferentes em relação ao tipo de congelamento e descongelamento.

Germination, carbohydrate composition and vigor of cryopreserved Caesalpinia echinata seeds

The present study investigated the germination and vigor of Caesalpinia echinata (Brazilwood) seeds stored at negative temperatures. Recently harvested seeds were cryopreserved at -18º or -196ºC and periodically evaluated for germination, seed vigor and carbohydrate composition. The temperatures did not influence the germination percentages or vigor. The germination percentage decreased from 88% in recently harvested seeds to 60% after 730 days of storage. The different temperature and storage times tested did not affect the vigor seed germination as indicated by the measures of plant growth and survival. The different temperatures used did not cause changes in the carbohydrate composition. The tegument cell walls were rich in lignin, arabinose and xylose. The cytoplasm of the cotyledons and embryos had high levels of glucose, fructose, and sucrose. The cryopreservation technique here presented was effective in the conservation of Brazilwood seeds for the medium term.