Dry matter production and panicle characteristics of high yield and good taste indica hybrid rice varieties

Indica hybrid rice(Oryza sativa) production aims to achieve two crucial targets: high yield and good taste. This study selected three types of indica hybrid rice according to grain yield and taste value, including high yield and good taste(HYGT), low yield and good taste(LYGT), and high yield and poor taste(HYPT), to analyze yield components,corresponding growth characteristics, and rice taste quality. When values were averaged across varieties and years,there were almost no differences in taste value between HYGT and LYGT;HYGT showed a significant increase in yield,owing to a higher number of panicles and spikelets per panicle, with a respective increment of 16.2 and 20.6%. The higher grain yield of HYGT compared with LYGT was attributed to three key factors: a higher leaf area index(LAI) during heading, a higher ratio of grain to leaf, and a higher biomass accumulation at maturity. HYGT and HYPT achieved similar high yields;however, HYGT had more panicle numbers and lower grain weight. In addition, HYGT showed a significantly higher taste value than HYPT, attributed to its significantly lower protein and amylose contents, with reductions of 8.8and 15.7%, respectively. Lower protein and amylose contents might be caused by a proper matter translocation from vegetative organs to panicle. This study suggested that reasonable panicle characteristics and translocation efficiency from vegetative organs to panicle during heading to maturity are the key factors in balancing yield and rice taste quality.These results will provide valuable insights for rice breeders to improve the grain yield and quality of indica hybrid rice.

Interaction Between Ustilaginoidea virens and Rice and Its Sustainable Control

Ustilaginoidea virens is a common rice pathogen that can easily lead to a decline in rice quality and the production of toxins pose potential risks to human health.In this review,we present a comprehensive literature review of research since the discovery of rice false smut.We provide a comprehensive and,at times,critical overview of the main results and findings from related research,and propose future research directions.Firstly,we delve into the interaction between U.virens and rice,including the regulation of transcription factors,the process of U.virens infecting rice panicles,and the plant immune response caused by rice infection.Following that,we discuss the identification and characterization of mycotoxins produced by the pathogenic fungus,as well as strategies for disease management.We emphasize the importance of comprehensive agricultural prevention and control methods for the sustainable management of U.virens.This knowledge will update our understanding of the interaction between U.virens and rice plants,offering a valuable perspective for those interested in U.virens.

Screening Rice Germplasm with Different Genetic Backgrounds for Cadmium Accumulation in Brown Rice in Cadmium-Polluted Soils

To screen rice germplasm with different genetic backgrounds for cadmium(Cd)accumulation in brown rice from common cultivated rice,we monitored grain Cd concentrations and characterized their patterns of 54 main varieties planted at two sites[Fuyang(FY)and Changshan(CS)in Zhejiang Province,China]with both low and high Cd-polluted levels.We found most varieties got higher Cd levels than 0.2 mg/kg in the Cd-polluted soil with the normal agronomic management,which suggested high risk of Cd exposure from the two sites.High Cd accumulation pattern was found in hybrid rice,but it differed between subspecies.Moreover,varieties with the same female or male parent may have different Cd accumulation capacities,meaning that the environment factors should be considered to screen low-Cd-accumulation varieties.

Rapid Determination of Silicon Content in Rice

A method for rapid determination of silicon content in rice was introduced. The reliability of this method was verified by using a recombinant inbred line （RIL） population of rice cross Zhenshan 97B / Milyang 46. Two hundred and forty-nine RILs were transplanted in two replications. Simple correlation coefficients on the silicon content in the hull, flag leaf and stern in rice between duplicate samples of 498 rice materials were 0.97954, 0.97026 and 0.98848, respectively. Ten representative samples were selected for measurement using the high-temperature alkaline fusion method. Simple correlation coefficient between the silicon contents determined by the high-temperature alkaline fusion method and by the present method is 0.9993.

Effects of Planting Methods on Levels of Common Pesticides and Heavy Metals in Dendrobium officinale

The levels of common pesticides and heavy metals in Dendrobium officinale grown from 2012 to 2014 were measured, and three planting methods were used in 2014. The quality of plant husbandry improved during the study period. Thirteen types of pesticides were detected in D. officinale grown in 2014 and antimicrobials, including carbendazim, difenoconazole and azoxystrobin, were evident in 61.53% of plants. These three pesticides constituted 72.33% of all the antimicrobials detected. Planting methods affected the levels of pesticides and heavy metals. Trellising in plastic sheds was optimal, being associated with the lowest amounts of both pesticides and heavy metals. Both cadmium（Cd） and lead（Pb） levels were high in treed plants, whereas Cr, As and Cu levels were the highest in potted plants.