Authors:Qi Yang, Gang Xie, Sanping Chen and Shengli Gao
compound [Ni 3 (Hdatrz) 6 (sca) 2 (H 2 O) 4 ]sca·11H 2 O. The X-ray structure analysis reveals the bonding mode of two ligands with Ni 2+ . TG-DTG of the investigated compound is discussed. The enthalpy change of the reaction of formation in water at 25 °C
The optimum condition for setting the single channel analyzer /SCA/ has been studied with respect to the time required for data acquisition in Mössbauer spectroscopy. It has been found that, regardless what the peak height to background ratio may be, for most practical purposes the best point to cut off the constant background is where the intensity of the Mössbauer peak drops to about 20% of its full height.
Authors:M.A. Adebayo, A. Menkir, S. Hearne and A.O. Kolawole
The quest for precise and rapid phenotyping of germplasm is increasing the interest of breeders and physiologists in the application of remote sensing techniques in maize breeding. Twenty-four drought-tolerant maize inbred lines were crossed using a modified North Carolina II mating scheme to generate 96 single-cross hybrids. The parents and the hybrids were evaluated under full irrigation and drought stress conditions in the dry seasons of 2010 and 2011 at Ikenne, southwest Nigeria. Normalized difference vegetation index (NDVI) was recorded at 3- and 8-leaf growth stages. Hybrids differed significantly for NDVI. Both general (GCA) and specific (SCA) combining ability effects were significant for NDVI measured at 8-leaf stage under both irrigation regimes, with GCA accounting for 53% of the total variation under full irrigation. Both additive and non-additive genetic effects played significant roles in the inheritance of NDVI. The females GCA effects for grain yield was positively correlated with females GCA effects for NDVI (r = 0.72, p < 0.0001) and the male GCA effects for grain yield was also correlated with males GCA effects for NDVI (r = 0.78, p < 0.0001) at 8-leaf stage under full irrigation. These results indicate that live green biomass accumulation in maize could be identified through early screening of a large number of genotypes using NDVI for developing productive hybrids.
Authors:T. Spitkó, L. SÁgi, J. Pintér, C. Marton and B. Barnabás
The breeding of hybrid maize now has a history of over 100 years. In 1908, George H. Shull was the first to report on the high yields, great uniformity and homogeneity of hybrids derived from a cross between two inbred lines. Following this discovery, consistent self-fertilisation over a period of six to eight generations was found to be an extremely efficient method for developing maize lines. From the mid-1970s, however, with the elaboration of the monoploid (
) and microspore culture (
) techniques, it became possible to develop homozygous lines within a year.With the help of an efficient plant regeneration system based on anther culture, large numbers of doubled haploid (DH) lines can be produced. In the course of the experiments the seed of DH plants selected over several years was multiplied and crossed with Martonvásár testers, after which the hybrids were included in field performance trials in three consecutive years (2005–2007). The aim was to determine whether the field performance of hybrids developed in this way equalled the mean yield of standards with commercial value. The data also made it possible to calculate the general (GCA) and specific (SCA) combining ability of the parental lines, indicating the usefulness of the parental components in hybrid combinations and expressing the extent to which a given line contributes to yield surpluses in its progeny.A total of 52 maize hybrids were evaluated in the experiments in terms of yield and grain moisture content at harvest. The combinations, resulting from crosses between 12 DH lines, one control line developed by conventional inbreeding and four testers, were found to include hybrids capable of equalling the performance of the standards, and four DH lines were identified as improving the yield level of their progeny. As the experiment was carried out on a very small number of genotypes, the results are extremely promising and suggest that, if the range of genotypes used to develop DH lines is broadened and the sample number is increased, it will be possible in the future to find maize hybrids, developed with
DH parental components, that surpass the performance of commercial hybrids.
Combining ability and heterosis were calculated for fourteen lines of linseed in a line × tester mating design using twelve lines and two diverse testers in two different environments. The hybrids and parental lines were raised in a completely randomized block design with three replications to investigate seed and fibre yield and their component traits. Genetic variation was significant for most of the traits over environments. Combining ability studies revealed that the lines KL-221 and LCK-9826 were good general combiners for seed yield and most of its components, whereas LMH-62 and LC-2323 were good general combiners for yield components only. Moreover, KL-221 was also a good general combiner for fibre yield. Similarly, B-509 and Ariane were good general combiners for fibre yield and most of its components. Among the specific cross combinations, B-509 × Flak-1 was outstanding for seed yield per plant and B-509 × KL-187 and LC-2323 × LCK-9826 for fibre yield per plant, with high SCA effects. In general, the hybrids excelled their respective parents and the standard checks for most of the characters studied. Based on the comparison of mean performance, SCA effects and the extent of heterosis, the hybrids LC-2323 × LCK-9826 and B-509 × KL-221 appeared to be the most promising for both seed and fibre yield. Other promising combinations were LC-2323 × KL-210 and B-509 × Ariane for seed and fibre yield, respectively. The superiority of LC-2323, LCK-9826, KL-221, B-509 and Ariane as good general combiners was further confirmed by the involvement of these parents in the desirable cross combinations.
Authors:M. Durosinmi, J. Ojo, A. Oluwole, O. Akanle, W. Arshed and N. Spyrou
Instrumental Neutron Activation Analysis (INAA) and Proton-Induced X-ray Emission (PIXE) analysis (employed as a complementary technique) have been used to determine the concentration of 11 elements in blood samples and its components erythrocytes and plasma obtained, from three groups of subjects in Nigeria viz: sickle cell anaemia (SCA) subjects, subjects with sickle cell trait and normal control subjects. The results suggest that SCA subjects have significantly higher concentrations of Na, Cl, Ca and Cu in their whole blood and erythrocytes and a higher concentration, of Cl and Cu in their plasma relative to the control subjects. Furthermore, a significantly lower concentration of K, Fe, Zn, Se, Br and Rb were found in the whole blood and erythrocytes of the SCA subjects as compared to the controls while the concentration of K and Fe in the plasma of the SCA subjects were however, found to be significantly higher than that of the control group. The study also shows that there was no significant differences between the concentration of these 11 elements in the group with sickle cell trait and the normal control group.
Authors:J. Srdić, S. S. Mladenović-Drinić and Z. Pajić
A diallel cross between ten maize inbred lines was carried out to estimate genetic parameters for grain yield and determine the heterosis and combining abilities of the inbreds and their crosses. Highly significant values for both GCA and SCA were found concerning this trait. The genetic distance (GD) of ten inbreds was evaluated using protein and RAPD markers. The GD based on protein markers ranged from 0.094, found between two lines of the same origin, up to 0.359 between two pairs of inbreds originating from different heterotic groups. Similar results were obtained with RAPD, where both extremes were found among the same F1 combinations. The reliability of the application of molecular markers was confirmed by the highly significant values of the correlations between GD/heterosis and GD/SCA, especially based on RAPD.
A field experiment was conducted in three low moisture areas in Ethiopia to study general and specific combining ability (GCA and SCA) for developmental, panicle and grain traits. Twenty-four parents (6 male sterile lines and 18 fertility restorers or testers) were used along with their 108 crosses. Combining ability analysis through a line × tester set for 14 agronomic traits in three environments and on a pooled basis revealed the importance of both additive and non-additive genetic effects. However, the predominance of additive components was observed in the inheritance of most traits studied. Environments also influenced the GCA and SCA effects. The female genotypes ICSA-10, ICSA-15 and ICSA-30, the testers ICSR-14 and KLCTENT # 17DTN and the crosses ICSA-30 × KCTENT # 17DTN, ICSA-30 × ICSR-16, ICSA-15 × KCTENT #17DTN and ICSA-10 × ICSR-14 exhibited the highest and significant SCA effects for yield and some of its components, indicating their importance in hybrid development for lowland areas of Ethiopia.
The fruit yield and quality of hot pepper, Capsicum annuum L., is very low in Ethiopia mainly due to the lack of improved cultivars. The objective of this study was to evaluate the combining ability for yield and yield contributing characters in order to apply an appropriate breeding methodology for the improvement of yield and the contributing characters. Seven diverse cultivars, two local cultivars and five introduced promising inbred lines, were crossed in a half-diallel. The parents and F1s were grown at Melkasa Agricultural Research Center in 1999 and 2000. The experiment was arranged in a randomized complete block design with three replications of ten plants per row. The green fruit yield and eight yield contributing characters were recorded from eight plants in each replication. The analysis of variance and estimates of GCA and SCA were significant for most of the characters studied. Significant GCA and SCA values were recorded for most of the characters, revealing that both additive and non-additive gene effects were involved in genetic control. A lower average degree of dominance was also recorded for some of the characters. Although none of the parents was a good general combiner for all the traits, some parents showed high GCA effects for some of the economic traits, suggesting that these parental lines could be considered simultaneously while formulating a breeding programme for improving fruit yield and yield contributing characters. The majority of the crosses also depicted significant SCA effects in the desirable directions.