WATER DEFICIT AFFECTS RECEPTIVITY OF MAIZE SILKS
WATER DEFICIT AFFECTS RECEPTIVITY OF MAIZE SILKS
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DOI：
10.2135/cropsci1993.0011183x003300020013x
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发表时间：
1993-03-01
期刊：
影响因子：
2.3
通讯作者：
WESTGATE, ME
中科院分区：
文献类型：
--
作者：
BASSETTI, P;WESTGATE, ME
玉米(Zea Mays L.)花期干旱降低结实率即使发生了授粉。为了测试低的蚕丝水势(psi(W))是否会降低蚕丝的接受性，我们研究了两个在温室中生长的杂交种的蚕丝发育、花粉-丝素相互作用和籽粒结实，这两个杂交种在蚕丝从壳中出现后暴露在短暂的水分亏缺中。低丝psi(W)直接影响丝绸的发育。随着真丝psi(W)的降低，蚕丝的伸长受到抑制，当真丝psi(W)低于-0.8 Mpa时，丝绸没有生长。在第一批蚕丝出现后3d内用低psi(W)抑制蚕丝的伸长，可延缓蚕丝衰老(基丝组织的崩塌)。然而，类似的水分亏缺加速了蚕丝的衰老。蚕丝发育的变化对籽粒结实有直接影响。低丝psi(W)降低了SET 20~40%3DAFS，并几乎完全降低了SET 5DAFS。当psi(W)在-1.0~-1.3 Mpa之间授粉时，90%的蚕丝中可观察到花粉管，但每丝的花粉管较少。当蚕丝psi(W)较低时，试管生长缓慢，但只有在蚕丝衰老后，试管才不能到达卵巢。这些结果表明，低psi(W)施加<；4 DAFS限制籽粒集主要是通过导致卵巢内的发育衰竭，而不是失去丝素功能。低psi(W)施加>；5 DAFS限制仁，加速蚕丝衰老。因此，开花期的水分亏缺会导致玉米失去对蚕丝的接受能力，但只有在蚕丝从壳中露出后5天，才会出现低的蚕丝psi(W)。
Drought during anthesis decreases seed set in maize (Zea mays L.) even if pollination occurs. To test whether low silk water potential (psi(w)) decreases silk receptivity, we examined silk development, pollen-silk interaction, and kernel set in two hybrids grown in a greenhouse and exposed to a brief water deficit after silks emerged from the husks. Low silk psi(w) directly affected silk development. Silk elongation was inhibited as silk psi(w) decreased, and no growth occurred at silk psi(w) below - 0.8 MPa. Silk senescence (collapse of basal silk tissue) was delayed, compared with controls, when silk elongation was arrested by low psi(w) within 3 days after the first silks appeared (DAFS). A similar water deficit 5 DAFS, however, hastened silk senescence. The change in silk development had a direct effect on kernel set. Low silk psi(w) decreased set 20 to 40% 3 DAFS, and decreased set almost completely 5 DAFS. Pollen tubes were observed in > 90% of silks pollinated at psi(w) between - 1.0 and - 1.3 MPa, although there were fewer tubes per silk. Tube growth was slow at low silk psi(w), but tubes failed to reach the ovary only after silks had senesced. These results indicate that low psi(w) imposed < 4 DAFS limited kernel set primarily by causing developmental failure within the ovary, not loss of silk function. Low psi(w) imposed > 5 DAFS limited kernel set by hastening silk senescence. Thus, water deficits at anthesis can cause loss of silk receptivity in maize, but only when low silk psi(w) occurs > 5 d after silks emerge from the husks.