Study On The Drought Resistance Of Seven Ground Cover Plants Of Liliiaceae

Drought has been the main stress factors restricting plant growth and development. Nowadays garden plants which have good ability of drought resistance are more popular in the ecological diversity garden. Ground cover plants is the largest family in the garden plants, most of them has good shade tolerance, But also sensitive to soil water stress, so the drought resistance of ground cover plants is the key to improve the drought tolerance of the whole green space system.In the paper, firstly made a survey on species and landscape application of ground cover plants of Liliaceae which has good shade tolerance in Shenzhen. The references record that:there are54widespread kinds of ground cover plants of Liliaceae in Shenzhen, belonging to15genuses.The investigation showed that:there are13species of ground cover plants of Liliaceae are widely used in the Green Park of Shenzhen currently, belonging to6genuses.Secondly, based on the investigation results, the drought resistances of seven ground cover plants of Liliaceae which are well-known in the area of southern China were studied by using potted-seedling experiment. Their physiological and biochemical change regulation were compared by measuring7index, including the permanent wilting rate, leaf water-losing rate, relative water content, relative electric conductivity, malondialdehyde content, soluble sugar content, free proline content, which was under the condition of soil water stress. The results showed that7experimental plants were all good at drought resistance which means plants of Liliaceae may have drought resistance potential. Based on the comprehensive analysis with subordinate function, the conclusion was as follows: Ophiopogon japonicus var. nana had very strong ability of drought resistance. Asparagus cohcinchinensis (Lour.) Merr.、Aspidistra elatior Blume、 Dianella ensifolia (Linn.) DC.’Silvery Stripe’ were just followed. Chlorophytum comosum (Thunb.) Baker ’Variegatum’、 Hemerocallis×hybrida ’Stella deoro’ had medium ability of drought resistance. But Dianella ensifolia (Linn.) DC. had relative weakly ability of drought resistance.Finally, based on the drought resistance evaluation results, Ophiopogon japonicus var. nana、Asparagus cohcinchinensis (Lour.) Merr.、Aspidistra elatior Blume、Dianella ensifolia (Linn.) DC.’Silvery Stripe’、 Chlorophytum comosum (Thunb.) Baker ’Variegatum’、 Hemerocallisxhybrida ’Stella deoro’ with kind of relatively drought resistance were selected for long-term(4months) experiment. According to the permanent plant wilting rate, set three gradients of soil relative water content as follows: adequate soil water (60%-65%), moderate drought (40%-45%), and moderate drought severe drought (20%-25%). Determined the effect of biomass increment, specific leaf area and root/shoot ratio; diurnal variations of net photosynthetic rate and diurnal variations of transpiration rate in three gradients of soil relative water content. The results showed that:6experimental plants could keep their ornamental in different lower limit of the soil relative water content:for Aspidistra elatior Blume is20%-25%; for Ophiopogon japonicus var. nana, Asparagus cohcinchinensis (Lour.) Merr., Dianella ensifolia (Linn.)DC.’Silvery Stripe’are40%-45%; for Chlorophytum comosum (Thunb.)Baker ’Variegatum’、 Hemerocallisxhybrida’Stella deoro’are60%-65%.According to the comprehensive analysis of6ground cover plants of Liliaceae, it was indicated that the indexes reflecting to tolerant ablities were:the permanent wilting rate, relative water content, relative electric conductivity, malondialdehyde content; biomass increment, specific leaf area, root/shoot ratio; diurnal variations of net photosynthetic rate, diurnal variations of transpiration rate.