Generation means analysis of phytic acid and inorganic phosphorus contents in corn (Zea mays L)

This study reported the effects of gene action in controlling the traits with respect to the contents of phytic acid (PA) and inorganic phosphorus (InP) in corn seeds by using an analysis of six generation means (P1, P2, F1, F2, BC1, and BC2) in six crosses of elite inbred lines. The crosses of Ki16 x Ki10, Ki52 x Ki51, and 30A10-S10-14-1-2 x Ki23 for the PA content and 30A10-S10-11-1-10 x Ki20 for the InP content were adequately described by the additive-dominance model which it showed the importance of the additive and dominance gene effects on both the PA and InP traits. The non-allelic gene action (epistasis) study in the PA trait in the three crosses of 30A10-S10-11-1-10 x Ki20, Ki51 x Ki20, and C5219041-S6-95 x Ki23 revealed that there was a statistically significant difference only in the cross 30A10-S10-11-1-10 x Ki20 which had an additive x additive gene action. For the study on the non-allelic gene action of the InP trait in the five crosses of Ki16 x Ki10, Ki51 x Ki20, Ki52 x Ki51, 30A10-S10-14-1-2 x Ki23, and C5219041-S6-95 x Ki23, although the different gene actions were observed, the gene effects of dominance and dominance x dominance were significantly inherited for the InP content in many crosses. From the yield study in the six generations in the six crosses, both heterosis and the additive gene effect were prominent action in the yield performance. Moreover, correlation between yield and the PA content in the crosses was positive

Screening of phytic acid and inorganic phosphorus contents in corn inbred lines and F1 hybrids in tropical environment

Seeds of inbred lines and F1 hybrids of corn (Zea mays L) grown from late rainy season of 2007 to early rainy season of 2009 at the National Corn and Sorghum Research Center, Thailand, were analyzed to determine the contents of phytic acid (PA) and inorganic phosphorous (InP). The PA contents in the tested inbred lines and F1 hybrids ranged from 800 to 1,000 mg per 100 g seed. The two groups of Ki inbred lines (Nursery no. 122 in the 2007 late rainy season), based upon the analysis of PA, were categorized to low (L) (the value o

Short-term physiological responses to drought stress in seedling of tropical and temperate maize (Zea mays L.) cultivars

Understanding of the response of tropical and temperate maize (Zea mays L.) to drought is the first step for tolerant temperate maize improvement. Eight maize hybrids were used to investigate physiology responses under drought stress, four of them were tropical maize and the others were temperate maize. Results showed that there were different drought tolerances but similar trends in both tropical maize and temperate maize. Gas exchange parameters revealed different strategies of maize under the stress. In our study, most of the temperate hybrids maintained open stomata to keep a higher photosynthesis rate at the beginning of stress, while the other hybrids decreased stomatal conductance. Compared to temperate maize, the tropical maize had higher antioxidase activity and greater physiological parameter variation among hybrids. KS5731 and ZD309 had stronger drought resistance among tropical and temperate maize hybrids separately. Tolerant hybrids maintained active photosynthesis, have higher osmotic adjustment ability and antioxidase activities but lower malonaldehyde content than the sensitive ones. Our results led to a better understanding of the physiological responses of tropical and temperate maize plants to drought stress and may provide an insight of breeding for drought resistance in maize

Correlations between the contents of phytic acid and inorganic phosphorous and downy mildew resistance of corn inbred lines

Seeds of corn inbred lines collected at the National Corn and Sorghum Research Center (NCSRC), Kasetsart University, were analyzed to determine the contents of phytic acid (PA) and inorganic phosphorous (InP). These 28 and 29 inbred lines were cultivated at the NCSRC (in the 2008 late rainy season and 2009 early rainy season) to evaluate their resistance to corn downy mildew caused by Peronosclerospora sorghi. Results showed that the values of the PA, InP contents and downy mildew infection were statistically different among these inbred lines in both seasons. However, there were no correlations between the contents of either PA or InP and downy mildew infection