Micronutrient Accumulation in Conilon Coffee Berries with Different Maturation Cycles

ABSTRACT The number of days between anthesis and maturation of conilon coffee berries varies according to the genotype. Thus, it is believed that periods of greater nutrient demand for fruit formation also vary according to the genotype, directly influencing fertilizer management. The goal of this study was to establish accumulation curves for the micronutrients boron, copper, iron, manganese, and zinc in conilon coffee trees with different maturation cycles. The experiment was conducted in Nova Venécia, State of Espírito Santo, Brazil, during the reproductive cycle of the 2010/2011 crop year. Four coffee genotypes with different maturation cycles (early, intermediate, late, and super-late) were studied. A completely randomized experimental design was used with five replications. The treatments correspond to the accumulation of B, Cu, Fe, Mn, and Zn in the berries every 28 days in the period from flowering to harvest. The early, intermediate, and late genotypes accumulated Fe, Cu, and Mn in a similar manner, with sigmoid curves, whereas the super-late genotype accumulated these nutrients exponentially. Zn was accumulated by all four genotypes following a sigmoid curve. The early, intermediate, and late genotypes accumulated B linearly, whereas the super-late genotype accumulated B following a sigmoid curve. The maturation cycle of the genotype must be taken into account to apply the correct rate of micronutrient fertilization in coffee plantations.

In vitro culture as a part of Brassica oleracea var. capitata L. breeding

Fourteen genotypes of cabbage (Brassica oleracea var. capitata L.), that are a part of Institute for Vegetable Crops collection, were tested for their ability to regenerate shoots in vitro. Five of them are early, while nine are late genotypes. Lateral buds from plants grown in the open field were used as explants. In all genotypes, lateral buds showed the high percentage of shoot formation, ranged from 80% to 100%. They were incubated on Murashige and Skoog?s (MS) media supplemented with 1.0 and 2.0 mgl-1 of benzyladenine (BA) or 1.0 mgl-1 6-furfurylaminopurine (KIN) in combination with 0, 0.5 and 1.0 mgl-1 indole-3-butyric acid (IBA). The BA- supplemented media were optimal for both growth and multiplication of shoots. In both groups of genotypes, the highest index of multiplication (IM) was achieved on medium supplemented with 2.0 mgl-1 BA and 1.0 mgl-1 IBA, in R9 early genotype (IM 8.53) and K1 late genotype (IM 10.06). R5 early and in K29 and K75 late genotypes had no multiplication on medium with 1.0 mgl-1 KIN (IM 1.00). Also, in all genotypes the lowest index of multiplication was observed on media supplemented with KIN (without or in combination with IBA).

QTLs and their interaction determining different heading dates of barley in Australia and China

Heading date is a major determinant of the regional and seasonal adaptation of barley varieties. The dogma is that introduced germplasm is more likely to be adapted if it is derived from a similar latitude. However, barley germplasm introduced from similar latitudes of South-East Asia is extremely early heading in the Australian environments and vice versa. A doubled-haploid population from a cross of an Australian barley Galleon and a Japanese barley Haruna Nijo was evaluated for heading date in Australia (Perth, 31°56′S) and China (Wuhan, 30°33′N) under normal autumn sowing, late sowing in the field, and extended-light glasshouse conditions. One major QTL was identified on chromosome 5H under the three conditions in China. The single QTL accounted for up to 50% of phenotypic variation for heading date. The Australian variety contributed to late heading date. Two QTLs on chromosomes 4H and 5H were detected for controlling heading date in Australia. The QTL/QTL interaction contributed up to 35.8% of phenotypic variation for heading date in Australia, which is the major reason for the extremely early heading date of the Japanese variety in the Australian environment. The chromosome 5H QTL was detected at the same chromosomal location when the population was grown in either China or Australia. In both environments the Australian variety contributed to the late heading date. Selection against the Japanese alleles of chromosomes 4H and 5H QTLs could eliminate the extremely early genotype in Australia and selection against the Australian allele of chromosome 5H QTL could eliminate the extremely late genotype in China when Australian and Japanese germplasms are used in the breeding programs.