Abstract:

This study aimed to identify the responses of total flavonoids and total saponins contents in fruits and leaves
during the fruiting stages of balsam pear (Momordica charantia. L. var. lan shan da bai) to different levels of soil moisture
and environmental factors. Balsam pear was grown at three levels of soil moisture, namely 90%–100%, 70%–80% and
50%–60% field capacity (FC), respectively. Meanwhile, the environment factors, including atmospheric temperature,
relative humidity, and photosynthetically active radiation, were also analyzed. The results were obtained as follows: 1) as
a whole, the contents of total flavonoids in leaves were higher than in fruits, whereas the opposite result was observed for
total saponins.; 2) treatment with 90%–100% FC at the full fruit stage and with 70%–80% FC at both early and later fruiting
stages was more suitable for the accumulation of saponins in fruits; however, soil moisture content had no significant effect
on the accumulation of saponins in leaves during the entire fruiting period; in addition, 50%–60% FC treatment favored
the accumulation of flavonoids in both fruits and leaves; 3) correlation analysis showed that soil moisture and atmospheric
relative humidity were correlated positively with total saponins but negatively with total flavonoids, and higher atmospheric
temperature and photosynthetically active radiation were beneficial to the accumulation of flavonoids but unfavorablefor
the accumulation of saponins. In conclusion, treatment of 70%–80% FC in combination with moderate shade, cooling and
moisture is more suitable for the accumulation of saponins while treatment of 50%–60% FC in combination with elevated
light intensity, temperature and humidity can promote the accumulation of flavonoids.

Key words: total saponins, total flavonoids, balsam pear, soil moisture