Fig. 1 Statistical box diagram of initial flowering time for 25 sugarcane parents in 7 crossing seasons “〇” represents mild outliers; the upper and lower edge lines represent the maximum and minimum values respectively except the outliers; the upper and lower lines of the box represent the upper and lower quartile respectively, which including the range of 50% of the data set; the bold black line represents the median.

Fig. 2 Statistical box diagram of initial flowering time in 7 crossing seasons for sugarcane parents “〇” represents mild outliers; the upper and lower edge lines represent the maximum and minimum values respectively except the outliers; the upper and lower lines of the box represent the upper and lower quartile respectively, which including the range of 50% of the data set; the bold black line represents the median.

Fig. 3 Statistical box diagram of heading rate for 25 sugarcane parents in 7 crossing seasons “〇” represents mild outliers; the upper and lower edge lines represent the maximum and minimum values respectively except the outliers; the upper and lower lines of the box represent the upper and lower quartile respectively, which including the range of 50% of the data set; the bold black line represents the median.

Fig. 4 Statistical box diagram of heading rate in 7 crossing seasons for sugarcane parents “〇” represents mild outliers; the upper and lower edge lines represent the maximum and minimum values respectively except the outliers; the upper and lower lines of the box represent the upper and lower quartile respectively, which including the range of 50% of the data set; the bold black line represents the median.

Fig. 5 Statistical box diagram of pollen dyeing rate for 25 sugarcane parents in 7 crossing seasons “〇” represents mild outliers; the upper and lower edge lines represent the maximum and minimum values respectively except the outliers; the upper and lower lines of the box represent the upper and lower quartile respectively, which including the range of 50% of the data set; the bold black line represents the median.

Fig. 6 Statistical box diagram of pollen dyeing rate in 7 crossing seasons for sugarcane parents “〇” represents mild outliers; the upper and lower edge lines represent the maximum and minimum values respectively except the outliers; the upper and lower lines of the box represent the upper and lower quartile respectively, which including the range of 50% of the data set; the bold black line represents the median.

Fig. 7 Pollen microscopic examination of GT28 in 2017/2018 crossing season