Characteristic of Inflorescence Development and Selection of Less Pollen of Male Populus tomentosa

During 2018 and 2019, 9 germplasm of male Populus tomentosa with less pollen were selected from 15 ones in Hebei province. From February to March, observation was carried out on male inflorescence development and morphology, pollen production and anther development. The result showed that male inflorescence began to expand and elongate in mid-February, anthers cracked and pollen disseminated in early or mid-March. The inflorescence development of male poplar lasted for about 30d. The inflorescence of P. tomentosa ‘No. 11’, P. tomentosa ‘1603’, P. tomentosa ‘1601’ and P. tomentosa ‘No. 7’ was larger in volume. The fresh and dry weight of pollen from P. tomentosa ‘1603’, P. tomentosa ‘No. 15’, P. tomentosa ‘1602’, P. tomentosa ‘No. 5’ and P. tomentosa ‘No. 7’ was lower, especially the first two cultivars. The experiment demonstrated that the anthers of tested P. tomentosa had development retardation in the middle and late stage, pollen grain adhesion and lower anther cracking rate, leading to the failure of normal pollen dissemination.