土壤水分对川早枇杷头花开花结果特性和花朵保护酶活性的影响

为研究土壤水分对早熟枇杷头花开花结果特性及花朵保护酶活性的影响,采用盆栽控水试验,以特早熟枇杷芽变新品系川早枇杷为材料,设置正常灌溉、轻度水分胁迫、中度水分胁迫和重度水分胁迫处理,研究了土壤水分对川早枇杷头花开花结果特性和花朵保护酶活性的影响。结果表明:在土壤水分胁迫下,川早枇杷头花花序长度、花序宽度、花序支轴数及花朵数减少,花蕾长、花蕾宽、花药长、花药宽、花丝长和花柱长均缩短,柱头可授性及柱头黏液分泌均减弱,花粉活力及发芽率降低,且这些指标均随土壤水分胁迫的加剧而呈降低或减弱的趋势。在土壤水分胁迫条件下,川早枇杷头花花朵的保护酶(SOD、POD和CAT)活性均低于正常灌溉条件,且随土壤水分胁迫的加剧而降低幅度增大,说明川早枇杷头花花朵的抗氧化能力在水分胁迫条件下减弱,生物膜受损害程度增加。在土壤水分胁迫条件下,川早枇杷头花花朵坐果数、坐果率均低于正常灌溉条件,且随土壤水分胁迫的加剧而呈降低的趋势;但3种土壤水分胁迫条件均提高了川早枇杷头花果实种子数量。因此,花期土壤水分胁迫是造成川早枇杷头花坐果率低的重要原因。

Effects of Soil Moisture on Blossom,Fruit-setting and Protective Enzyme Activity of Chuanzao Loquat in the First Florescence

The first florescence of the precocious loquat is in the dry season.To study the effects of soil mois ture on blossom,fruit-setting and protective enzyme activity of loquat,the pot experiment of controlling water,with a new very precocious loquat line Chuanzao loquat as the materials,was designed to be 4 soil moisture treatments:normal irrigation,mild water stress,moderate water stress and severe water stress.The effects of soil moisture on blossom,fruit-setting and protective enzyme activity of Chuanzao loquat in the first florescence were studied.The results showed that the water stress of soil decreased the flower cluster length,flower cluster width,flower cluster number of secondary peduncle,number of flowers on the top of inflorescence and total number of flowers,and also decreased the flower buds length,flower buds width,anther length,anther width,silk length and style length of Chuanzao loquat.The water stress of soil reduced the stigma receptivity,mucous secretion of stigma,pollen vitality and pollen germination percentage of Chuanzao loquat.With the increase of soil moisture stress,these items of Chuanzao loquat had the decreasing trend.Under soil moisture stress,the protective enzyme (superoxide dismutase,peroxidase and catalase) activity of the first florescence of Chuanzao loquat was lower than the normal irri gation condition,and had the decreasing trend with the increase of soil moisture stress,indicating that the antioxidant ability of first florescence of Chuanzao loquat was weakened under water stress,and the damage degree of cell membrane increased.Under soil water stress,the fruit number and fruit setting rate of first florescence of Chuanzao loquat were lower than the normal irrigation,and had the decreasing trend with the increase of soil moisture stress.However,three treatments of soil water stress increased the seed number of first florescence of Chuanzao loquat.Therefore,soil water stress is the main factor causing the low fruit setting rate in flowering period of Chuanzao loquat.