Pest insects of rice in China

In China, rice faces serious pest problem. About 347 pests attack rice plant in field, and 103 pests damage stored grain, powder and bran. Of those, at least 83 species can cause serious economic losses during rice production or storage. There exist four types of distribution of rice pests: 1. About 47.5% distribute over the south of the Qinling Mountain and the Huanghe River i.e. the South China rice cropping ares belonging to the Oriental region, e. g. Tryopryza incertulas (Walker). Catagella abjurella Walker, Chilo auricilia (Dudgeon), Susumia exigua Butler, Nephotet     

Properties of the pigment in black rice

Pigment was extracted from pericarp of black rice variety Zixiangnuo. The effects of several factors, including pH, light, chemical reagents and foodstuff additives on the color, solubility and heat stability of the pigment were observed. The color of the pigment varied with different acid conditions. When the pH was below 3, a stronger absorption peak at 495nm was observed. If the pH was between 3 and 10, there was a platform in 400-495nm. No obvious absorption peak in visible light region was found when pH was above 10. As the pH increased, the color of the pigment changed, from deep red to light red until to yellowishbrown, e.g. pH 0-2, deep red; pH3-4, red pH5-6, quite red; pH9-10, faint red; pH11, faint brown yellow; pH12, light brown yellow; pH13, yellowish brown; pH14, deep yellowish brown. The change of color was reversible. The pigment was quite stable under nature light conditions. At pH 1, it was basically unchanged within 10 d under sunlight or within 60 d under indoor nature light. However,     

Introduction of Brazil upland rice in China

In 1992,the government of Brazil presented nine crop varieties to China.One of them is Brazil up-land rice IAPAR9.It was evaluated for commercial usage in China by China National Rice Re-search Institute(CNRRI).From 1993 to 1997,IAPAR9 was planted in Jiangxi Province in large area successfully.The     

An outline of rice breeding in China

Since the end of 1940s, China has ever taken breeding and popularization of elite varieties as the important measures for yield increase of rice. About 1,000 varieties and 100 hybrid rice combinations have been developed, among which 284 ones haveonce been cultivated over an annual area of 667,000 ha. There have been several breakthroughs in rice breeding in China leading to leaps of the rice production.     

Inheritance of leaf color in purple rice

Two purple rice mutants OPL and PL184 were se lected from normal green rice lines Ketan Nangka and W6184 in 1988 and 1990 respectively. No segre gation was found in two sequent generations. When these two purple rice were crossed with each other. the F_1 and F_2 showed all purple color and no segregation occurred also, inferring that their leaf color maybe controlled by the same genotype. If these two purple rice lines crossed with other 23 normal green rice lines including 12 TGMS indica lines, 2 PGMS japonica lines, 2 WA indica lines. 1 BT indiea lines,4 convenLional indica varieties, and 2 conventional japonica varieties, their F_1 showed all normal green color.     

Conservation of wild rice germplasm in Guangdong

Located in the subtropical zone of South China, Guangdong Province is rich in wild rice genmplasm. The 3 wild rice species, being indigenous to China, O. rufipogon Criff, O. officinalis Wall and O. meyeriana Baill are dispersed over the province. About 1,354 habitats of wild taxa have been found scattering over 71 counties in the province ( see table ).     

Effects of rice or wheat residue retention on the quality of milled japonica rice in a rice–wheat rotation system in China

In rice–wheat rotation systems, crop straw is usually retained in the field at land preparation in every, or every other, season. We conducted a 3-year-6-season experiment in the middle–lower Yangtze River Valley to compare the grain qualities of rice under straw retained after single or double seasons per year. Four treatments were designed as: both wheat and rice straw retained(WR), only rice straw retained(R), only wheat straw retained(W), and no straw retained(CK). The varieties were Yangmai 16 wheat and Wuyunjing 23 japonica rice. The results showed contrasting effects of W and R on rice quality. Amylopectin content, peak viscosity, cool viscosity, and breakdown viscosity of rice grain were significantly increased in W compared to the CK, whereas gelatinization temperature,setback viscosity, and protein content significantly decreased. In addition, the effect of WR on rice grain quality was similar to that of W, although soil fertility was enhanced in WR due to straw being retained in two cycles. The differences in protein and starch contents among the treatments might result from soil nitrogen supply. These results indicate that wheat straw retained in the field is more important for high rice quality than rice straw return, and straw from both seasons is recommended for positive effects on soil fertility.     

Quality of principal released rice varieties in China

Most of the cultivated rices in China are nonwaxy japonica and indica varieties. According to the the survey of the rice quality on 262 principal released varieties (every variety has been popularized over 6,600 ha) by CNRRI, the average of brown rice recovery is 80% (70—82%) and the head rice recovery is 54% (40—67%)in indica varieties. Most indica varieties have medium long and bold grains with low translucency and high rate of chalky grain and chalkiness. In addition, they possess high amylose content, low to medium gelatinization temperature and medium gel consistency with average 9.8% protein content (6.8% to 13.8%). Only a few indica varieties have extra long or slender grains, high translucency, medium or low amylose content, and soft or hard gel consistency. None of them have high     

Overexpression of potassium channel genes in rice plant

China's potassium fertilizer mainly depends on import and the utilization efficiency of K fertilizer was only 30%. So it is very important to enhance utilization efficiency and to reduce its applying amount by improving nutrition characteristics of plant with bioengineering techinques. Potassium channel genes AKT1 and KAT1 were the genes involved in K uptake. To investigate the role of heterogeneous K channel genes in the enhancement of K absorbing, genes AKT1 and KAT1 were transferred into four rice varieties, i. e. Zhonghua 8, Zhonghua 9, Zhonghua 13, and     

Origin and cultivation history of rice in China

According to the documental accounts, the distribution of wild rice (O.perennis), the ancestor species of cultivated rice in ancient China is possibly more northward than in the modern times. The earliest rice grains unearthed from the Neolithic sites existed along the lower and middle reaches of the Yangtze River.     

Selection of proto clonel variation in rice Daguzao

The regenerated plants from protoplast o fDaguzao, a traditional indica rice variety, were obtained in Beijing and then transplanted in a green house in Nanjing in winter 1988. Systematical investigation on agronomic traits of 360 plants from 6 strains was conducted in the field in 1988-1990. Their chromosome number and some isozymes were examined in the lab.     

Mechanization of irrigated rice cropping regions in China

The mechanization of rice production in China has experienced a comparatively long and an undulating process. The full-scale making of mechanization of irrigated rice cropping regions was started at the mid 1960's, later than that of upland cropping and its average level of mechanization operation also lower than the average level of the country. During this peiod, however, a series of mechines were created, which adapted to the characteristics of rice cropping regions in China, and the foundation was laid for the later paddy field machinery. For example, transplanting machine (created in 1956), boat—shaped tractors (1961), paddy field ploughing and harrowing serial (1974), and single wheel plowing machines (1979) etc.     

Genetic analysis of quality traits in intersubspecies crosses of rice

Indica and japonica rices are two subspecies of Asia cultivated rice. Their grain qualities exist a significant difference. The objective of this paper is to study the genetic control of quality traits in intersubspecies crosses of rice.     

NEWS：Introduction of Brazil upland rice in China

In 1992, the government of Brazil presented nine crop varieties to China. One of them is Brazil upland rice IAPAR9. It was evaluated for commercial usage in China by China National Rice Research Institute (CNRRI).     

Genetic diversity of rice blast fungus in northern China

The characterization of population structure ofblast pathogen contributes to the rational de- velopment and the deployment of blast-resis-tant cultivars.To study the population struc- ture of blast pathogen in northern China,DNA fingerprinting of 192 blast isolates col-lected in 8 representative districts in 1996 wasconducted by using Pot 2-PCR method. Sampling sites and number of haplotypeswere listed in Table.DNA isolation,DNAamplification,and gel running were done as     

Geographical distribution of wild rice germplasm resources in China

There are at least 20 species of wild rice in theworld.Three wild rice species have been foundin China,i.e.O.rufipogon Griff.,O.officinalis Wall.,and O.meyeriana Baill,distributing in Fujian,Jiangxi,Hunan,Tai- wan,Guangdong,Guangxi,Yunnan,andHainan provinces(see table and figure).Theregion covers from southernmost Ya County,Hainan Province(18°9′N)to northernmostDongxiang County,Jiangxi Province(28°14′     

Distribution of the Si-deficiency rice soil in Hubet Province

There are about 1 million ha of Si-deficiency paddy soils in Hubei Province, Practically, it is essential to study the Si nutrient status in those Si-deficiency rice soil and its regional distribution before the application of Si-fertilizer.     

Quantitative trait loci analysis of leaf morphology in rice

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