| The genetic analysis of the main related properties of maize starch can provide theoretical basis for the high-starch maize breeding. In this study, 9 maize inbred lines with different starch content were selected as parents to make 72 crosses by means of GriffingI diallel crosses. The heredities of the starch content and the starch RVA viscosity properties were studied. The starch accumulation of three high-starch inbred lines selected from 9 maize inbred lines was analyzed. The main conclusions were as follows:1. The heredity of starch content was mainly affected by the additive effect. The heterosis of the maize starch content was positive. The starch content of hybrids was significantly correlated with that of the middle-parent and the female parent.2. There were no significant relationship found between the SCA effect of the starch content in hybrids and that of their parents. The SCA effect of the offsprings could not be simply infered from the GCA effect of their parents. The parent 2 and parent 5 had high starch content and high GCA, and can be used as breeding resources for high starch maize breeding in the future.3. Significant differences of starch RVA viscosity properties were found in parents and their hybrids. Differences in hybrids were bigger than that in parents. Over-MP heterosis was detected in Breakdown (BD) and Setback(SB), respectively; over-LP heterosis in Peak Viscosity (PV), Trough Viscosity (TV), Final Viscosity (FV), Peaktime (PT), and Pasting Temperature (PTP), respectively.4. PT, TV and BD of the hybrids were significantly correlated with that of their parents and the middle-parent. SB of the hybrids was significantly correlated with that of their middle-parent. While Final Viscosity (FV), Peak Time (PT) and Pasting Temperature(PTP) of hybrids were not. Correlation coefficients of PT, TV, FV and SB in hybrids between the male parent were greater than those with the female parent. BD, PT and PTP of the hybrids were more affected by the female parent.5. GCA of nine parents was that the parent 8 was the highest in PV and BD, parent 6 in TV, parent 5 in FV, parent 9 in SB, parent 3 in PT, parent 7 in PTP, respectively. The SCA of the hybrids was that 8×5 was the highest in PV, 8×9 in TV, 3×5 in BD, 7×5 in FV, 6×5 in SB, 5×3 in PT, 5×7 in PTP, respectively.6. PV, TV, BD, FV and SB had relatively high broad sense heritability (H2B), while PT and PTP had relatively low H2B. The narrow sense heritability (H2N) of starch viscosity was also very high except that of BD, SB, PT and PTP. Both additive and dominance effects were almost equally important factors of genetic variance for PV, SB, PT and PTP. Additive effect was the main factor of genetic variance for TV and FV. Dominance effect was the main factor of genetic variance for BD.7. During the grain filling period of 10～66 days after pollination(DAP), the starch content of parent 5 was always higher than that of parent 2 and 9 in 3 high-starch cultivars. The starch contents of three cultivars reached the highest value on the 45 DAP. The starch accumulation rates of all the 3 high-starch cultivars were the highest at the period of 17～24 DAP; the accumulation rate began to slow down after 24 DAP. The starch accumulation rates of cv. Shan 814 and Huangzao 4 showed a trend of ups and downs latterly, indicanting that the environment affected the starch synthesis in cv. Shan 814 and Huangzao 4. |
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