Relationship between differ- ential gene expression pat- terns in functional leaves of maize (Zea mays L.) at milk filling stage and heterosis using cDNA-AFLP

The genetic mechanism of heterosis has been one of the most challenging subjects in life science since the 20th century. However, because of the complexity of its genetic basis and the limitations of research methods and means, there was no substantial progress in the research of heterosis from the beginning of the 20th century to the 1990s. The development in molecular biology and bio- technology, especially that in quantitative trait loci (QTL) mapping methods, has made it possible to resea…

Relationship between differ-ential gene expression pat-terns in functional leaves of maize (Zea mays L.) at milk filling stage and heterosis using cDNA-AFLP

To understand the molecular mechanism of maize heterosis, differential gene expression patterns in the functional leaves of 35 maize hybrids relative to their parents involving 10 elite inbreds at milk filling stage were analyzed by using cDNA-AFLP. The correlation analyses of various differential expression patterns with the performance and heterosis of main maize agronomic traits were evaluated. The main results were as follows: For uniparental specific expression, significant positive correlations were detected with the performance of seed weight per ear and 100-seed weight at 0.01 and 0.05 probability levels respectively. For biparental specific expression, significant negative correla-tions were detected with the performance of ear diameter and seed weight per ear at 0.01 probability level. For uni-parental specific expression, significant positive correlations were detected with the heterosis of ear diameter and seed weight per ear at 0.01 and 0.05 probability levels respectively. For biparental specific expression, significant negative cor-relation was detected with the heterosis of ear diameter at 0.05 probability level. However, for F1-specific expression, for fragments detected only in one parent and F1, and for fragments detected only in two parents or only in F1, no sig-nificant correlation was detected with the performance or heterosis of all agronomic traits surveyed.