Investigation of genetic diversity in irradiated maize lines and its relation to hybrid performance20-26Views:147
Knowledge of genetic diversity among available parental lines is fundamental for successful hybrid maize breeding. The aims of this study were to estimate (1) genetic similarity (GS) and genetic distance (GD) (based on Jaccard index) in four maize inbreed lines; (2) to classify the lines according to their GD and GS; (3) to determine hybrid performance based on GD and heterosis for yield ability in 4x4 full diallel system. We used morphological description and AFLP (amplified fragment length polymorphisms) for estimation genetic polymorphism in four maize inbred lines. We estimated the applicability of genetic similarity in SC and reciproc hybrids for prediction of their performance.
Three primer combinations were used to obtain AFLP markers, producing 207 bands, 70 of whit were polimorphic. The dendogram based on genetic similarities (GS) and genetic distance (GD) and morphological description separated four inbred lines into well-defined groups. Morphological description just with AFLP analysis showed reliable results. In view of genetic distance, the UDL 1 line and their linear and reciprocal crosses showed significant heterosis effect, which was confirmed by heterosis calculation based on grain yield.
Comparison of Variability among Irradiated and Control Inbred Maize Lines via Morphological Descriptions and Some Quantitative Features70-73Views:58
Knowledge of genetic diversity in breeding material is fundamental for hybrid selection programs and for germplasm preservation as well. Research has been done with nine irradiated (fast neutron) and four non-treated inbred lines. The aims of this study were (1) to investigate the degree of genetic variability detected with morphological description (based on CPVO TP/2/2) in these materials, (2) to compare the genetic changes among irradiated and non-irradiated maize inbred lines (based on some quantitative features). The irradiation did not change any of the characteristics clearly in positive or negative way, which can be related to the fact that the effect of induced mutation on genetic structure cannot be controlled. From the irradiated lines we have managed to select plants with earlier ripening times and better phenotypes. We could distinguish 3 main groups by the morphological features; these results match our expectations based on pedigree data. Markers distinguishable on the phenotypic level (e.g. antocyanin colouration, length of tassels) were significant in all lines.
Evaluation of blue and red corn landraces239-243Views:71
Corn breeding can be successful only on a broad base of genetic material. The expansion of breeding aims includes the research of germplasm materials. In our experiments, we examined 11 blue, purple and red exotic corn varieties on two locations in Hungary. We conducted a complex study to obtain more information. We studied several morphological and phenological features and determined the most important qualitative parameters (protein, fat, ash). We applied the Tassel Area Index (TAI) under Hungarian conditions and compared it with the pollen producing ability of different genotypes. Results show that there are great opportunities in exotic corn varieties. Their quality exceeds that of the yellow ones in many cases. There are significant differences in yield and nutritional parameters. The favorable nutritional composition is not coupled with great productivity. Based on their flowering time and their agronomical features, they can be cultivated under Hungarian conditions as well. They match the new breeding aims, so they can be used as functional food or energy plants. With their high pollen producing ability and TAI, they can be utilized as markers in future pollen research.
Gene Bank Developed by Induced Mutation for Selection45-49Views:65
Heterosis breeding in maize caused gene erosion by using uniform inbred lines. In order to strengthen the genetic base, we established a gene bank containing lines with broad genetic variability, resistance and adaptability. The maize gene bank is a result of our work in the past two decades.
The gene bank originated from treatments of maize seeds of hybrids and inbred lines with fast neutrons. The 1500 maize lines have great genetic variability which can be exploited after strict assessment and selection. As a result of the past several years, P 26, P 61 and P 62 lines have been released after DUS investigation in 2001.
Investigation of directions of crossing in maize (Zea mays L.)43-48Views:85
In Hungary, we examined eight features of twelve direct cross hybrids over a period of three years. The twelve hybrids were derived from direct and reciprocal crosses of four parental lines. We did not find significant differences in the cases of stalk diameter and leaf number in the average of 3 years in any of the hybrids. Statistically explainable differences in primary branches were observed in hybrids UDH5 and UDH8 and also in UDH6 and UDH11. It was evident in both instances that degrees of heterosis in reciprocal crosses far exceeded those of direct ones. High tassel branch number was dominant over the low one; consequently, parents with higher tassel numbers enforced their effects during the formation of this trait in hybrids. We experienced positive correlation (r=0.67**) between plant height and main ear height. A positive correlation (r=0.89**) was also found between the tassel length of the main axis above the lowest and the upper side branch. We observed a medium correlation (r=-0.42**) between the number of primary lateral branches and plant height. The number of primary lateral branches showed the highest heterosis. These results can be utilized in practical selection and seed production.
Possibilities of selection and production of blue and ornamental corn (Zea mays L.)15-19Views:82
The cultivation of alternative crops has an important role in world agriculture. Their market share is continuously growing in the food industry sector. In the present study, we show the cultivation and breeding perspectives of ornamental and blue corn. There exists possibility to cultivate ornamental corn in Hungary. There are many cultivars of ornamental corn, with various kernel colors, husks, stalks and leave colors. Blue corn is unique among other corns. Blue corn higher in protein, iron and zinc than commercial dent corn. Pests affective ornamental and blue corn are the same as those of other commercial corns. Ornamental and blue corns need to be grown a minimum of 500 m away from commercial yellow dent corn to minimize any cross pollination which may result in off-color kernel. Our aim in the presentation of this review was to broaden Hungarian literature.
Determining factors of test weight in maize (Zea mays L.)40-42Views:90
Most domestic maize production products are sold on markets abroad. Among the increasingly restrictive quality requirements, the demand for the measurement of test weight has also appeared. This measurement is not unfamiliar in the case of other cereals, such as wheat and barley, but it has not been applied widely in maize. It is likely for this reason that we have such little information and research available on this topic. In this study, we show the current state of this field with references from domestic and international literature.
The density of maize is the weight of a particular volume and the most frequent unit is the test weight (kg/hl). This physical quality factor plays important roles in the storage, transport and mill industries. The value of test weight is influenced by many factors. The most important ones are the moisture content of grains, drying temperature, drought, precipitation, early frost, and the hybrid characters of a given genotype (grain type, FAO number). In general, the grain with higher moisture content has lower test weight and the higher temperature during (above 82°C) desiccation also leads to unfavourable values. Factors such as a drought interval after flowering, early frost in the case of hybrids with higher FAO numbers, injuries by insects, as well as fungal infections also influence the structure and moisture content of the maize grain.
In the future, broader studies (hybrid testing, application of new agrotechnical elements) will be needed for understanding of the factors effecting test weight.