【摘要】 研究初步表明,早衰性品系的上部三张叶片绿色面积和叶色消退比正常品种为快,约早4～8天。¹⁴C 标记指出,在开花期穗及上部三张叶片的¹⁴C 同化物分配为:45%运向茎杆等供继续生长之用;30～35%运向籽粒;20～25%自存。开花后10天约76～81%运向籽粒;11～16%自存;运向茎杆等只占7%。在此期间,早衰性品系分配到籽粒的¹⁴C 同化物比正常品系少5%。标记部位留存则多5%。其原因可能由于叶片早衰使同化物输出效率低所致。分析表明,早衰性品系穗及倒二叶、倒三叶¹⁴C 同化物输出效率低于正常品系4.0～23.0%。开花后20天内,由于叶片早衰引起的籽粒产量损失率约为5～6％。由于开花后早衰性品系倒二叶、倒三叶比正常品系衰老早5～8天,而此时70%左右的光合产物运向籽粒。因此,在进行早熟小麦育种时,应尽量选育后期叶片不早衰的材料。在栽培上,应重视穗、粒肥的施用,以延长上部叶片功能,增加粒重。更多还原

【Abstract】 Results obtained from preliminarily studies indicated that the three uppermost leaves of the early-senescent lines died 4-8 days earlier than those of the normal varieties of wheat.This phenomenonwas especially serious with the 2nd and 3rd leaves from the top.In early-senescent lines,the totalamount of assimilates distributed to the grains from ears and leaves decreased by 5% at flowering timeand in 10 days after flowering as compared with that in normal lines;and the outflow efficiency ofassimilates from ears and the uppermost 2nd and 3rd leaves was 4-23% lower than that of normallines,but the amount remained was 2-12% higher.As distinguished from normal lines,the outflowefficiency of the flag leaf of the earlysenescent lines increased by 2-9%.Owing to the early-senescence of leaves,the grain yield lose reached about 5-6% in 20 days afterflowering.It is significant,therefore,in breeding practice that strains which didnot gave sigus ofearly-senescence at later stage should be selected.In order that the functional period of the upper lea-ves could be prolonged and the grain weight could be increased,special attention should be paid tothe application of fertilizers for ear and grain formation.更多还原