不同土壤水分胁迫对澳洲坚果花期生长的影响

EFFECTS OF SOIL WATER STRESS ON THE GROWTH OF MACADAMIA AT THE FLOWERING STAGE

云南西双版纳澳洲坚果种植区在开花坐果和果实发育期处于严重干旱的土壤条件下,此期澳洲坚果植株经不同土壤水分处理,结果表明:在严重干旱条件下,花器官发育不良,植株的花序和柱头长度缩短,花粉萌发率低,花粉管生长速度慢,坐果率低,同时幼果生长受抑制等。灌溉有利于花序和柱头的正常伸长、能提高花粉萌发率、坐果率和果实大小。不同品种、不同器官对干旱的反应不一样,Kau和Pahala的花粉活力比O.C.对水分胁迫反应敏感,Pahala的受精坐果能力对干旱的反应比O.C.敏感,Kau幼果生长对严重干旱胁迫反应最敏感,Kau幼果的生长速率慢于Pa hala和O.C.。正常灌溉植株的综合效应达到最佳。花期干旱季节进行60%田间持水量灌溉有利于澳洲坚果的授粉受精,提高坐果率及产量。

Severe drought frequently occurs in Xishuang Banna of Chinese Yunnan province, where Macadamia plants are consequently exposed to severe soil water stress conditions at the flowering and fruit-setting stages. An experiment reported in this paper showed that different water treatments had significant effects on Macadamia plants. Water stress decreased significantly the length of the anthotaxy and stigma, pollen germination, fruit setting percentage and fruit size. The responses to water stress varied with cultivar and organ. The pollen vitality of the two cultivars Kau and Pahala and fruit setting of Pahala were more sensitive to drought than those of O.C. Young fruit growth of Kau was most sensitive to drought. Maintenance of a soil moisture of 60% of field capacity through irrigation was favorable for the pollination, fertilization and fruit setting of Macadamia.