| Plug in the breeding conditions due to the highly centralized of production and particularity of plug structure, the excessive growth of the plants is a very serious problem. It is a kind of simple and convenient method with instant effect to use plant growth retardants (PGRs) to control the phyiology growth of plants.As to this, this thesis selected cucumber and tomato as test materials, studied the retardant effects of different concentration of PP333 (50 mg·kg-1, 100 mg·kg-1, 500 mg·kg-1, 1000 mg·kg-1), S3307(0.1 mg·kg-1,0.2 mg·kg-1, 0.4 mg·kg-1, 0.8 mg·kg-1), CCC(2000 mg·kg-1, 4000 mg·kg-1,6000 mg·kg-1, 8000 mg·kg-1) and B9(6000 mg·kg-1, 9000 mg·kg-1, 12000 mg·kg-1,15000 mg·kg-1), and identified the best concentration and mixed proportion. After treatment the seeds ofФ12 cm dish on the Light incubator for germination test; another part of planting hole in the 128 set in a glass greenhouse. The physiology were investigated with the following results:1. test of germinationSeed germination percentage , germination rate and long of bud were controlled, root length and root vigor of seed were promoted and fresh weight of seed was reduced with treatment of cucumber and tomato seed by PP333,S3307,CCC and B9. P3,S2,C3 and B2 were optimal concentration for cucumber. P2, S2, C3 and B1 were optimal concentration for tomato.2.1 Seedlings emergence percentage and seed vigor of cucumber were controlled with treatment of seeds by PP333, S3307, CCC and B9. P3, S2, C3 and B2 were optimal concentration for cucumber. Seedlings emergence percentage was increased, but seed vigor was decreased with the treatment of tomato seeds by PP333,S3307,CCC and B9. P1, S2, C2 and B1 were optimal concentration for tomato .2.2 Sound seedling index, stem diameter and root/shoot ratio were increased with treatment of seeds by PP333, S3307, CCC and B9. P3, S2, C3 and B2 were optimal concentration for cucumber. After 40 d of sowing, sound seedling index greater than the control , respectively 28%, 7%, 7% and 3%, and root/shoot ratio greater than the control, respectively 3.62 %, 14%, 25% and 26% for cucumber. After 45d of sowing, sound seedling index greater than the control , respectively 76%, 75%, 75%, 63% with the treatment of P2, S2, C3 and B1 for tomato. And root/shoot ratio greater than the control, respectively 34%, 62%, 24% and 14% with the treatment of P1, S2, C2 and B1 for tomato.2.3 The contents of chlorophyll were increased, but the leaf area was controlled with treatment of seed by PP333, S3307, CCC and B9. P3, S2, C3 and B2 were optimal concentration for cucumber. After 40 d of sowing, contents of chlorophyll greater than the control , respectively 22%, 41%, 11% and 9% with the treatment of P3, S2, C3 and B2 for cucumber.After 45d of sowing, contents of chlorophyll greater than the control , respectively 30%, 34%, 32%, 20% with the treatment of P2, S3, C3 and B2 for cucumber.2.4 The root vigor was increased with treatment of seed by PP333, S3307, CCC and B9. After 40 d of sowing, root vigorof cucumber greater than the control , respectively 37%, 50%, 55% and 24% with the treatment of P3, S2, C3 and B2. After 45d of sowing, root vigor of tomato greater than the control , respectively 31%, 76%, 43%, 20% with the treatment of P2, S3, C3 and B2.2.5 The activity of SOD, POD and CAT were increased treatment of seed by PP333, S3307, CCC and B9, so that it reduced harm of the accumulation of reactive oxgen species to cell. P3, S2, C3 and B2 were optimal concentration for cucumber. For cucumber seedlings, the activity of SOD, POD and CAT were greater than the control with the treatment of P3, S2, C3andB2,respectively 26%, 25% and 15%;23%, 30% and 25%;15%, 27% and 20%;26%,22% and 15%. For tomato seedlings, the activity of SOD, POD and CAT greater than the control with the treatment of P2,C3 and B2,respectively 26%,21% and 16%;28%,21% and 10%;27%, 24% and 15%, the activity of SOD greater than the control with the treatment of S3 by 30%, the activity of POD and CAT greater than the control with the treatment of S2 by 25% and 15%.2.6 The contents of Pro, osmotic regulation and resistance were increased with treatment of seed by PP333, S3307, CCC and B9. The contents of Pro were greater than the control with the treatment by optimal concentration of P3, S2, C3 and B2, respectively 22%, 29%, 22% and 20%. The contents of Pro were greater than the control with the treatment by P2, S3, C3 and B1 for tomato, respectively 21%, 25%, 25% and 17%.2.7 The contents of MDA increase were alleviated with the treatment of seed by PP333, S3307, CCC and B9, so that it reduced harm of membrane system of cell. The contents of MDA were lower than the control with the treatment by optimal concentration of P3, S2, C3 and B2, respectively 15%, 22%, 28% and 13%. The contents of MDA were lower than the control with the treatment by P2, S3, C2 and B1 for tomato, respectively 10%, 12%, 8% and 13%. |
