Effect of Seed-coating Agents on Rice Seeds with Dehiscent Glumes

In order to improve the utilization efficiency of hybrid rice seeds, the effects of seed-coating agents on hybrid rice seeds with dehiscent glumes were investigated. Total six kinds of seed-coating agents were selected, i.e., 20.5% imidacloprid ·prochloraz FS, 30.5% imidacloprid oprochloraz FS, 23.0% thiamethoxam · hymexazol·prochloraz FS, Ruisheng WS, Shileshi FS and Liangdun FS, and their effects of seeds of Longliangyou Huazhan and T You 272 were investigated. The results showed that when the percentage of glume-dehiscent seeds reached 10%, 20.5% imidacloprid .prochloraz significantly improved the germination rate of Longliangyou Huazhan, which was 4.33% higher than that in the control group, and the seedling rate of Longliangyou Huazhan remained unchanged; 30.5% imidacloprid. prochloraz did not improved the germination rate of T You 272, but improved its seedling rate, which was 7.66% higher than that in the control group. When the percentage of glume-dehiscent seeds reached 20%, 20.5% imidacloprid ·prochloraz and 30.5% imidacloprid.prochloraz improved the germination rate of T You 272 by 3.50% and 4.83%, respectively, and its seedling rate did not decline. In conclusion, seed-coating agents have certain repair effect on glume-dehiscent rice seeds; 20.5% imidacloprid ·prochloraz and 30.5% imidacloprid ·prochloraz could improve the efficiency of Longliangyou Huazhan and T You 272 with small amounts of glume-dehiscent seeds.

Effect and Mechanism of Cold Tolerant Seed-Coating Agents on the Cold Tolerance of Early Indica Rice Seedlings

To better understand the effect and mechanism of cold tolerant seed-coating agents on the cold tolerance of rice seedlings, the physiological and biochemical effects of four cold tolerant seed-coating agents （HET, YKJ, YKZYJ, and the ABA seed coating agents） on two early indica rice varieties were studied under chilling stress. The results showed that the rice seedlings treated with cold tolerant seed-coating agents under chilling stress maintained dramatically higher root vigor, POD, CAT and SOD activities, and chlorophyll content, had lower MDA content and electrolyte leakage, and accumulated more soluble sugar and free proline, when compared with the control without the treatment, and finally showed lower plant injury rate. It was indicated that the cold tolerant seed coating agent improved the ability of rice seedlings in resisting to chilling stress. YKZYJ was ranked the first in terms of the efficiency in cold tolerance among the four cold tolerant seed-coating agents tested.

Application Effects of Ultra-fine Powder Shaped Maize Seed Coating Agent in Spring Sowing areas in northeast China

The research explored adaptability maize seed coating agent in spring sowing and effects of ultra-fine powder shaped areas in northeast China. The results showed that germination potential and rate both improved around 5% and the num- ber of root increased by 4% in the treatments with ultra-fine powder shaped maize seed coating agent compared with the control group without seed coating. What＇s more, the treatments with ultra-fine powder shaped maize seed coating agent took advantages in terms of fresh weight of seeding, stem diameter, and dry weight. It is notable that control effects on underground insects performed the best, with per- centage over 94%, which is more excellent relative to other agents in markets. Therefore, ultra-fine powder shaped maize seed coating agent can be widely applied in spring sowing areas in northeast China, without side effects.

Effect of variety and seed dressing on emergence of high-oleic peanut under low temperature and high soil humidity conditions

Low temperature coupled with high soil moisture during sowing to emergence generally results in poor peanut stand,thereby posing a non-negligible threat to peanut production in north and northeast China.Five high-oleic(HO)peanut cultivars and 4 seed dressing treatments capable of controlling several diseases and insect pests along with untreated checks were used to find the best combinations to cope with the dual stresses during sowing to emergence period.High broad-sense hereditability estimates of seedling emergence indicated great potential for genetic improvement of this trait.Analysis of variance in the split-plot experiment showed that the main effects of variety and seed dressing and their interaction on seedling emergence were significant.Seed dressing treatments increased seedling emergence percentage by 2.09–35.00 percent points.Four of the 5 HO peanut cultivars yielded satisfactory results.For Huayu 665,Huayu 668 and Huayu 965,Huweisanbao may be the best option;for Huayu 962,Weilidan was highly acceptable.These combinations will be evaluated further in multiple environments before large-scale extension.

Regulation of Root-Knot Nematode Behavior by Seed-Coat Mucilage-Derived Attractants

Seed exudates influence the behavior of soil organisms,but howthis occurs remains unclear,particularly for multicellular animals.Here we show that compounds associated with Arabidopsis seed-coat mucilage regulate the behavior of soil-borne animals,specifically root-knot nematodes (RKNs).Infective RKN J2 larvae actively travel toward Arabidopsis seeds through chemotaxis.Analysis of Arabidopsis mucilage mutants demonstrated that the attraction of RKNs toArabidopsis seeds requires the synthesis and extrusion of.seed-coat mucilage.Extracted mucilage alone is not sufficient to attract RKNs,but seed-surface carbohydrates and proteins are required for this process.These findings suggest that the RKN chemoattractant is synthesized de novo upon mucilage extrusion but may be highly unstable.RKNs attracted by thismucilage-dependent mechanism can infect the emerging seedling.However,the attraction signal from seedling roots likely acts independently of the seed-coat signal and may mask the attraction to seed-coat mucilage after germination.Multiple RKN species are attracted byArabidopsis seeds,suggesting that this mechanism is conserved in RKNs.These findings indicate that seed exudate can regulate the behavior of multicellular animals and highlight the potential roles of seed-coat mucilage in biotic interactions with soil microorganisms.