光照对绿豆扦插苗不定根生长硼需求的影响

研究了光照状况对绿豆扦插苗不定根生长硼需求的影响.结果表明，当绿豆幼苗在光照强度(PAR)为50或100 μmol·m^-2·s^-1条件下连续生长10 d，外源供硼时扦插苗才能生长不定根，在该光照条件下连续生长6 d再遮黑4 d，无需外源供硼即可生长不定根；在PAR为180 μmol·m^-2·s^-1下连续生长6 d再遮黑4 d，需外源供硼才能保证不定根生长；在PAR为100 μmol·m^-2·s^-1条件下连续生长10 d时，每个下胚轴中自由态的硼总量仅为在此光照条件下连续生长6 d再遮黑4 d时的一半,这可能是在PAR为100 μmol·m^-2·s^-1时连续生长10 d需要外源供硼满足不定根生长的原因.

Effects of irradiance on boron requirement of Phaseolus aureus cutting for its adventitious root development

This paper studied the boron requirement of Phaseolus aureus cutting for its adventitious root development under different photosynthetic active radiation (PAR). The results showed that exogenous boron supply was necessary for the adventitious root development of the cutting under 10 days of PAR at 50 or 100 micromol x m(-2) x s(-1), but unnecessary under 6 days of this irradiance and followed by 4 days of darkness. Exogenous boron supply was also necessary for the rooting under 6 days of PAR at 180 micromol x m(-2) x s(-1) and followed by 4 days of darkness. When the PAR at 100 micromol x m(-2) x s(-1) was employed for 10 days, the amount of soluble boron in each hypocotyl of the cutting was only half of that under 6 days of this irradiance and followed by 4 days of darkness, which might be the reason of the necessity of exogenous boron supply for the rooting under 10 days of PAR at 100 micromol x m(-2) x s(-1).