Screening method for drought-resistant germplasm of Ophiopogon japonicus

A screening method for a drought-resistant germplasm of Ophiopogon japonicus, comprising steps:

• (1) collecting surviving Ophiopogon japonicus from a cultivated field and a wild condition under drought, introducing the collected surviving Ophiopogon japonicus to a conservation nursery of Ophiopogon japonicus germplasms, and selecting populations of the Ophiopogon japonicus germplasms with consistent apparent epigenetic traits in the conservation nursery of Ophiopogon japonicus germplasms for further evaluation after the introducing;
• (2) using an online geographic information system (GIS) software to extract rainfall including April rainfall, May rainfall, and June rainfall, of a main production area including Luxi Town, Laoma Town, Licheng Town, Lingxing Town, Liuying Town, Xinde Town, Yongming Town, and Jianshe Town in Santai County, Mianyang City, Sichuan Province, China of the Ophiopogon japonicus from a global climate database during a period of water demands from April to June for growth of the Ophiopogon japonicus, calculating monthly average rainfall from April to June, and converting the monthly average rainfall from April to June into a water supply;
• (3) setting 100±5%, 50±5%, and 35±5% of the water supply converted in the step (2) as a normal water supply, a moderate drought, and a severe drought of three water gradients according to the period of the water demands for the growth of the Ophiopogon japonicus under a natural condition, respectively;
• conducting drought stress simulation experiments on the populations of the Ophiopogon japonicus germplasms obtained in the step (1) under different drought conditions;
• (4) after setting the three water gradients, determining growth indicators and physiological indicators of the populations of the Ophiopogon japonicus germplasms under different drought stress conditions;
• wherein the growth indicators comprise chlorophyll, a number of new roots, lengths of the new roots, a number of leaves, widths of the leaves, and growth of leaf length, the physiological indicators comprise malondialdehyde (MDA), total superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and proline (Pro);
• and
• (5) applying a fuzzy mathematical evaluation method to comprehensively rank the growth indicators and the physiological indicators of the populations of the Ophiopogon japonicus germplasms, thereby evaluating a drought-resistant ability of the Ophiopogon japonicus and screening out the drought-resistant germplasm of the Ophiopogon japonicus,
• wherein the screening method for the drought-resistant germplasm of the Ophiopogon japonicus further comprises:
• planting the screened drought-resistant germplasm of the Ophiopogon japonicus to reduce water application amount and source under drought conditions during the period of water demands from April to June for growth of the Ophiopogon japonicus, so as to increase production of the Ophiopogon japonicus.