ASI, number of tassel branches and the days taken to grow from seeding to various growth stages.

Maize seeds were sown in flowerpots containing a naturally low-Pi soil (10 mg Pi kg−1 soil) with either no additional KH2PO4 (low phosphate, LP) or mixed with 600 mg KH2PO4 (sufficient phosphate, SP) per kilogram soil. The days from seeding to tasseling, flowering, pollen shedding and silking were recorded. ASI was measured and tassel branches were counted. Values are means ± SD (n = 5).*indicates statistically significant differences between transgenic lines and the wild type line under the same conditions at the 0.05 level, using Student's t-test. ASI, anthesis-silking interval; WT, wild type; L1, L2 and L3, transgenic lines; SP, sufficient phosphate and LP, low phosphate.