Biomedical subjects

Kangjing Liang

Publications and source records attributed to Kangjing Liang.

12 recordsLinked to original sources

PubMed2005

[Interactive effects between allelochemical substitutes].

In order to understand the allelopathic mechanisms of rice on weed, the allelochemical substitutes salicylic acid, p-hydroxybenzonic acid, cinnamic acid, vanillic acid and ferulic acid were used in an orthogonally gyrating regression experiment to study their interactive effects on the growth of barnyardgrass. The results indicated that whether the interactive effects between two substitutes, e.g., between salicylic and cinnamic acid or between salicylic and p-hydrobanzonic acid, were synergistic or antagonistic depended on the concentrations of each substitutes in the mixture. In the mixture of salicylic acid and p-hydrobanzonic acid, the effect of salicylic acid was synergistic at < 0.14 mmol.L(-1) but antagonistic at > 0.14 mmol.L(-1), while p-hydrobanzonic acid showed an antagonistic effect at > 0.425 mmol.L(-1). Salicylic acid at all test concentrations exhibited antagonism to cinnamic acid, while cinnamic acid had a synergistic at < 0.14 mmol.L(-1), but an antagonistic effect at >0.14 mmol.L(-1) on alicylic acid. The interactive effects between cinnamic and ferulic acid were all synergistic at test concentrations.

Cinnamates↗

PubMed2005

[Kinetic developmental genetics analysis of Hibiscus cannabinus plant height and stem diameter].

By using quantitative traits additive-dominance genetics model and developmental genetics model, this paper analyzed the developmental behaviors of gene expression for Hibiscus cannabinu plant height and stem diameter at its different growth stages. The results showed that at different growth stages, the unconditional and conditional genetics effects of plant height all showed dominance, while the additive effect was weak. No additive effect was found for stem diameter, but dominance effect was significant at each growth stage. Plant height and stem diameter all had active gene expression from July 28 to August 9, and from September 2 to September 14. There was no additive correlation between plant height and stem diameter, but positive dominance correlation was significant after August 21. The unconditional and conditional genetics effects of plant height and stem diameter were not completely the same. According to practice, conditional genetic analysis could indicate the gene expression more truly in the whole growth period. The ecological and genetics variation patterns of Hibiscus cannabinus plant height and stem diameter at different space-time growth stages implied by our research was of significance in Hibiscus cannabinus genetics and breeding in both theory and practice.

Genes, Plant↗

PubMed2005

[Corresponding analysis on rice grain heavy metal pollution in Fujian province].

By the methods of environmental statistics and corresponding analysis, this paper collected 38 early and late rice grain samples from the middle, southern, northern, western and eastern parts of Fujian Province to detect their Hg, As, Cr, Cd and Pb contents, and to search for the main factors resulting in the difference of rice cropping type in different regions, aiming at further understanding the relationships between heavy metal pollution and rice cropping type. The results showed that among the test heavy metals in grain, Pb had the highest percentage (100%) beyond the standard level, followed by Hg (78.95%), Cd (50.5%) and Cu (2.63%), while As did not surpass the standard level. It therefore could be concluded that Pb and Cd were the main factors resulting in the difference of rice cropping type in different regions. The results also showed that 38 rice grain samples could be clustered into 7 groups, indicating that different rice cropping types would significantly cause different degrees of heavy metal pollution, which suggested that the best way in controlling and preventing rice grain heavy metal pollution could be the approach of combining site-controlling with variety selection, based on the situation of different regions and rice cropping systems.

Cadmium↗

PubMed2005

[Changes of key enzyme activities in rice cultivars with different photooxidation-tolerance during grain-filling stage in early and late seasons].

Four rice cultivars with different photooxidation-tolerance characteristics during grain-filling stage in early and late seasons were selected to uncover the physiological and biochemical mechanisms of the correlation between rice photooxidation-tolerance and grain quality. The results showed that the parameters mean grain-filling rate (Gmean), time arrived to maximum grain-filling rate (T(max. G)), and 100-grain weight at the maximum grain-filling rate (T(max. G)) were relatively stable for the varieties adaptable to high light intensity, while on the contrary for those sensitive to photooxidation. The ADP glucose pyrophosphorylase and starch synthase activities of the varieties adaptable to high light intensity after grain-filling peaks had a less difference between early and late seasons than those sensitive to photooxidation, and the relative enzyme activities in the varieties adaptable to high light intensity changed coequally in early and late seasons.

Edible Grain↗

PubMed2004

[Evaluation efficiency of different bioassay methods on allelopathic potential of Oryza sativa].

In this paper, three bioassay methods, i.e., relay seeding in agar (RSA), relay seeding in silica (RSS) and seeding in rice root-exudation (SRE), were used to test the allelopathic potential of 8 rice cultivars on the target weed barnyardgrass (Echinochloa crusgalli). The results indicated that RSA was the ideal method for the bioassay, showing the highest efficiency in the evaluation of allelopathic potential. RSS and SRE had a lower efficiency than RSA, but these two methods showed the same tendency in evaluating the allelopathic potential of rice. RSA, the considered best bioassay method in this experiment, was used for 57 allelopathic rice germplasm screening, and 5 of them, i.e., Iguape Cateto, PI312777, Azucena, Taichung Native 1 and IAC25 performed the strongest allelopathic potential in the suppression on barnyardgrass.

Echinochloa↗

PubMed2004

[Weed-suppressive effect of phenolic acids].

Allelochemical substitutions salicylic acid, p-hydroxybenzonic acid, cinnamic acid, vanillic acid and ferulic acid were tested in a gyrating regression experiment to study the weed-suppressive effect of phenolic acids on the root growth of barnyardgrass. The results showed that cinnamic acid had a significant inhibitory effect, its square item regression coefficient being -6.18; salicylic acid, p-hydroxybenzonic acid and ferulic acid had the same trend of weed-suppressive potential as cinnamic acid, while vanillic acid had a different weed-suppressive effect from the others. The inhibition rate (IR) on the root growth of barnyardgrass reached its highest level (78.5%) when 0.06 mmol x L(-1) salicylic acid, 0.60 mmol x L(-1) p-hydrobenzonic acid, 0.24 mmol x L(-1) cinnamic acid, 0.02 mmol x L(-1) vannillic acid and 0.02 mmol x L(-1) ferullic acid were mixed together to apply.

Cinnamates↗

PubMed2003

[Molecular responses of rice (Oryza sativa L.) to the stress of lowly enhanced UV-B radiation].

The approach of mRNA differential display (DD) was used to analyze the gene differential expression of rice seedling subjected to lowly enhanced Ultraviolet-B radiation. The results showed that of the eighteen differential fragments, fifteen ones were different in expressional levels, another one was depressed, and the other two, named as RUVB1 and RUVB2 respectively, which could be recovered and re-amplified, were specifically induced. Sequence analysis for RUVB2 through Internet BLAST searching indicated that it was more than 95% identities with three rice ESTs, but very low similarity to others in the GenBank, and was mapped on the OSJNBb0091N21BAC(GenBank accession No.: AC091122) in Oryza sativa L.

Oryza↗

PubMed2003

[Heterosis and genetic correlation analysis of rice (Oryza sativa L.) grain weight development under different environmental conditions].

Two sets of test materials were derived from diallel cross among nine different types of selected rice varieties (lines). Based on the experimental data at different development stages of early and late rice, the estimation of heterosis and genetic correlation of rice grain weight at some development stages (0-->t) or at some special development phases (t--1-->t) was conducted by using additive-dominant genetic model and developmental genetic model for quantitative traits. The results indicated that the heterosis over mid-parent value based on population mean was not significant at 5% level at the early stages (1-12 d), and turned to positively significant as the development process proceeded in early rice. The heterobeltiosis based on population mean appeared to be small negative during the entire courses of grain filling. The heterosis over mid-parent based on population mean appeared to be positively significant at the early and middle grain filling stages (1-18 d), but became insignificant at the late stages (19-28 d) in late rice. The heterobeltiosis based on population mean appeared to be positively significant at the early grain filling stages (1-12 d), but turned to be significantly negative as the development process proceeded in late rice. It also indicated that the heterosis of grain weight development was beneficial to improve the quality of grain filling in late rice, compared to that in early rice. The genetic correlation between the grain weights per se at different stages and the final grain weight was mainly controlled by dominant effects, and became closer with the development process in the early rice, while by additive effects in the late rice. It's suggested that indirect selection of final grain weight throughout the process of grain filling would be more effective in late rice.

Edible Grain↗

PubMed2003

[Molecular ecological basis of high-yielding formation of rice and its application].

This paper introduced the developmental genetics and its molecular ecological basis of high yielding formation of rice in the past decade, and analyzed the advantage and the shortage of comparative physiological approach traditionally used in the research work on crop cultivation. It was emphasized to actively introduce the research contents and its methodology from relative disciplines to deeply understand the scientific issue, and suggested that the key to realize stable and high yielding of rice was to develop a rational cultivation system based on the properties of genetic effects on the traits in different developmental stages by controlling and regulating the traits governed by dominant effect genes and additive effect genes x environment in same direction, which was considered as the main characteristics and the technological innovation of modern crop genetic ecological cultivation science. Finally, the development trend of crop cultivation science shifting to molecular crop cultivation science was predicted and discussed.

Carbohydrates↗

PubMed2002

[Developmental genetic analysis of panicle dry weight of indica hybrid rice oryza sativa under different environmental conditions].

Four indica sterile lines (A) and corresponding maintainer lines (B) as well as five indica restorer lines, which varied in panicle dry weight, were used to create genetic populations of two generations according to incomplete diallel cross design (4 x 5). Analysis on panicle dry weight at different developmental stages based on tow-years experimental data was conducted by using additive-dominant developmental genetic models with genotype effects and genotype x environment interaction effects. The results showed that panicle dry weight was controlled by both genetic main effects and genotype x environment interaction effects in the whole developmental process. During the early-middle developmental periods (15 days after flowering), panicle dry weight was mainly governed by dominant effects, and dominant genes expressed with large amount. The meanwhile, positive effects produced by environmental factors appeared to be significant. Proper cultivation measure to create good external environment conditions for rice panicle was helpful to promote the expression of heterosis potential completely. Within the middle-late developmental periods (from the fifteenth day to the thirtieth days after flowering), additive effects played major role, and its genes expresed in the most active state. Genetic selection for panicle conducted in this period was expected to gain better genetic advancement.

Crops, Agricultural↗

PubMed2002

[Genetic ecology of rice allelopathy on receiver plant].

In this study, 5 parental rice lines with different allelopathic potential were employed in partial diallel cross (4 x 5) to get 10 groups of F1 seeds. After testing the inhibitory effects of 5 parents and 10 F1s under different environment at different leaf stage on the shoot length of receiver plant lettuce(Lactuca sativa L.), dynamic genetics of rice allelopathy and its genotype x environment effects were analyzed by using additive-dominant developmental genetic models. The results showed that additive and dominant effect genes expressed alternatively during 3-leaf stage to 8-leaf stage in rice seedling. As additive effect genes were pronounced at 7-leaf stage, dominant effect genes appeared to play the most important role at 3-leaf stage and 6-leaf stage but the two effect genes were equally important at 5-leaf stage and 8-leaf stage. Heritabilities analysis indicated that the general heritability in the narrow sense(HN2) was significant at 5-, 7- and 8-leaf stage, and decreased with increasing leaf stage. Rice allelopathy was significantly affected by genotype x environment (GE) interaction, suggesting that the environment of allelopathic rice development must be controlled for practical use.

Ecology↗

PubMed2002

[Screening methodology for rice (Oryza sativa) genotypes with high phosphorus use efficiency at their seedling stage].

Under hydroponic culture, the responses of rice (Oryza sativa) genotypes to low P stress were respectively evaluated by means of relatively-higher P concentration in a controlled system with insoluble phosphate source (Ca3 (PO4)2) and of relatively-lower concentration with 0.5 mg P/L in which NaH2PO4 was the soluble phosphate. Relative indices such as relative dry weight of tillers (RTW), total relative plant dry weight (RPW), relative number of tillers (RTN), relative dry weight of root (RRW), relative dry weight of shoot (RSW), relative leaf age (RLA) and relative plant height (RPH) were used to screen as the tolerant indices to P deficiency, and the correlations among screening criteria per se were analyzed. The results showed that there were significant differences of tolerant indices to P deficiency in the test rice genotypes. When the rice cultivars were exposed to low P stress with the relatively-higher P concentration to be screened, the relative tiller dry weight (RTW), relative shoot dry weight (RSW) and total relative plant dry weight (RPW) could be used as the better screening criteria, especially RTW was considered as a sensitive and reliable screening criterion because its coefficient of variation (CV) and the variable range of data among the test varieties should be large. However, when rice genotypes were grown in the stress condition with relatively-lower P concentration, the screening criteria were different, and it suggested that relative shoot dry weight (RSW) or total relative plant dry weight (RPW) was the best single screening criterion.

Genotype↗