ISSR molecular markers and anatomical structures can assist in rapid and directional screening of cold-tolerant seedling mutants of medicinal and ornamental plant in Plumbago indica L.

Plumbago indica L. is a perennial herb with ornamental and anticancer medicinal functions widely distributed in the tropics. It affected by temperature cannot bloom normally colder subtropical regions, which seriously affects its value. To create low-temperature resistance mutants enrich new germplasm resources, this study used tissue culture chemical reagent (0.5 mmol/L NaN 3 ) stress (0°C, full darkness for 48h) induction to target screen cold-resistance mutants. The results showed that ISSR band polymorphism ratio of 24 suspected mutant materials was 87.5%. DNA profiles 9 initially identified were altered. content plumbagin stems leaves examined, it found accumulation SA24 could be as high 3.84 times control, 0.5991%. There significant differences anatomical structures roots, leaves. mostly exhibited reduced root diameter (only 0.17-0.69 CK), increased stem (up 2.19 enlarged mesophyll cells, thickness 1.83 CK) specificity, are thought important different cold obtained In experiment, four cold-tolerant successfully screened according their morphological characteristics physiological indexes, mutagenesis efficiency 2.22% did not affect leaves, even higher than CK. responses SA15, SA19, SA23 low slower leaf wilting, light energy conversion efficiency, less MDA content, enzymatic activities antioxidant enzymes (SOD, CAT, POD) more soluble sugars proline content. These consistent response plants temperatures. cold- cultivated soil observed agronomic traits one year, mainly manifested delayed flowering entry into senescence stage. This provides rapid accurate technique identifying screening mutants, lays foundation future experiments on creation cold-resistant varieties.