Relationship between ethylene and the occur-rence of cytoplasmic malesterility in rice

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Rheological and Thermal Properties of Potato Starch

<正>Particle size, rheological and thermal properties of potato starch from Yunnan province of China was investigated. The particle size ranges from 0.429-102.3 μm determined by laser light-scatter. The major flow type of 6 w/v% potato starch was shear-thinning fluid even the shear rate up to 800·s-1, and the gel formed by 6 w/v% potato starch fell to weak gel for its little difference between G′ and G′′, high dependence on frequency and low value of G′(Pa). The hardness and cohesiveness of potato starch gel were 31.3 g and 131.9 g·s, respectively. The thermal properties of potato starch were also determined by DSC at the starch∶ water = 3∶ 1. The To, Tp, and △H of potato starch were 62.23℃, 67.31℃, and 2.22 J·g-1.     

Assessment of Various Factors Involved in the Tissue Culture System of Rice

To optimize conditions for an efficient embryogenic callus induction and plant regeneration from mature seeds of japonica rice cultivar Xiushui 11 and indica cultivar XC95, different factors such as plant growth regulators, casein hydrolysate, carbohydrate source and concentration, and various gelation conditions including gel type for callus induction and phyta gel concentration for shoot regeneration were studied in detail to determine their role in the system. Overall, induction of embryogenic callus in case of Xiushui 11 was the most efficient (67.2%) in the media supplemented with 2 mg/L 2,4-D, 3% sucrose and 0.8% agar while in case of XC95, 2 mg/L of 2,4-D combined with 0.5 mg/L of BAP and NAA generated the best result (61.2%). Inclusion of 0.3% agarose (pure form) or phyta gel further enhanced the callus induction efficiency (80%) in Xiusui 11. Higher concentration (300–500 mg/L) of casein hydrolysate was found to significantly inhibit the browning of calli in XC95. Role of cytokinin and phyta gel concentration was critical for shoot regeneration in both classes of rice. Increased strength of phyta gel was observed to enhance the shoot regeneration frequency. The optimal concentration of 2 mg/L and 3 mg/L for KT was necessary for higher differentiation frequency supplemented with 0.5% and 0.6% phyta gel in case of japonica and indica rice, respectively.     

Relationship between the eating quality and the physico-chemical properties of high grain quality rice in China

Relationship between eating quality (EQ) andphysico-chemical properties of 78 high grainquality rice varieties, 45 indica and 33 japoni-ca, were studied in 1995. The samples werecollected from different rice growing regions in20 provinces. The physico-chemical proper-ties, including grain length (GL), length towidth ratio (L/W), chalky grain rate (CG),chalkiness (CH), translucency (TR), gela-tinization temperature (GT, measured by alka-li spreading value), gel consistency (GC),amylase content (AC), and protein content(PC) were measured according to the standard     

Varietal Differences in Endosperm Structure Related to High-degree Polishing Properties of “Hattan Varieties” of Rice Suitable for Brewing Original Hiroshima Sake

Abstract

This study was conducted to clarify the effect of varietal differences in the endosperm structure on the high-degree polishing properties of Hattan varieties of rice suitable for brewing original Hiroshima sake. Four varieties were used: Hattan No.35, Hattan-nishiki No.1, Hattan-nishiki No.2, and Yamada-nishiki. Ellipsoidal-white-core grains occurred at a higher rate in Hattan-nishiki No.1 and No.2, whereas lined-white-core grains were observed at a higher rate in Hattan No.35 and Yamada-nishiki. Hattan No.35 and Yamada-nishiki showed low void polishing rates, and Hattan-nishiki No.1 and No.2 high void polishing rates after 50% polishing. Hattan-nishiki No.1 and No.2 showed inferior properties; that is, many broken and cracked grains, particularly cracked grains, after 50% polishing. The contents of broken grains and cracked grains in Hattan No.35 were higher than those in Yamada-nishiki and lower than those in Hattan-nishiki No.1 and No.2. In Hattan No.35 and Yamada-nishiki, fewer airspaces were observed between the amyloplasts at the center of the white-core as compared with Hattan-nishiki No.1 and No.2. This study showed that the differences in the endosperm structure of white-cores in the brewers’ rice grain are related to varietal differences in the tolerance to high-degree polishing.     

Caryopsis Development and Main Quality Characteristics in Different indica Rice Varieties

A comparison on the caryopsis development, rice quality characteristics and the size, shape, structure of the endosperm amyloplasts （starch granules） between two indica rice varieties was made, The main quality traits in Yangdao 6 were better than those in Xiangzaoxian 33; In the early period after fertilization the dry matter in Yangdao 6 was accumulated more slowly than that in Xiangzaoxian 33 but faster in the later period, and the starch was accumulated strongly in the later period; There were two kinds of amyloplasts： single and compound amyloplasts, being 4.4 um and 9.5 um in diameter on average with the range of 2.4-8.0 um and 5.7-19.5 um, respectively. In the case of Xiangzaoxian 33, most of the single amyloplasts were elliptic or round with loose arrangement and great difference in size, and the coefficient of variation was high. While in the Yangdao 6, most of the amyloplasts were single, well developed, polyhedral, crystalline and compactly arranged, and the coefficient of variation was low. The amyloplasts in the dorsal region of endosperm were developed better than those in the ventral and central regions. The chalkiness in the endosperm resulted from badly-developed and loose-arranged starch granules, which was closely relevant to the transport of filling materials.     

Characteristics of Gas Exchange and Chlorophyll Fluorescence in Different Position Leaves at Booting Stage in Rice Plants

To investigate the senescence of rice leaves at different positions at booting stage, gas exchange and chlorophyll fluorescence properties in leaves at different positions were examined by using six rice materials. The net rates of photosynthesis (Pn), stomatal conductance (gs), transpiration rate (E) and water use efficiency (WUE) decreased significantly with lowering of leaf positions, while intercellular CO2 concentration (Ci) had a little change, indicating that the decrease of photosynthetic rate was not resulted from the decrease of gs. The decrease of SPAD reading which had a close correlation with chlorophyll content was one of apparent reasons resulting in the decease of Pn. Further evidence by chlorophyll fluorescence showed that the photochemical efficiency of PSⅡ and its electron transport rate (ETR) decreased substantially with lowering of the leaf positions but the variable-to-maximum fluorescence ratio (Fv/Fm) and efficiency of energy conversion of open PSⅡ (Fv’/Fm’) remained rather stable, suggesting that primary limitation of Pn was suppression of electron transport of PSⅠ, and probably associated with carbon assimilation.     

Comparison of Grain Quality Characteristics Between F1 Hybrids and Their Parents in Indica Hybrid Rice

Sixteen widespread elite indica parents including seven CMS lines and nine restorer lines, and their 63 F1 hybrids were chosen to compare the eleven traits of grain quality. Overall results showed that the frequency of negative over-dominance, dominance and partial dominance was much higher than that of positive ones and heterosis, indicating that the values of F1 hybrids were generally lower than the means of their parents in quality characteristics. There existed apparent disparity in grain quality performance among F1 hybrids varied with the traits. The characteristics of chalky area percentage, chalky grain percentage, gel consistency and head rice recovery had a great variation in all kinds of tested heterosis indices including the mid-parent heterosis index, over high-value parent heterosis index and over low-value parent heterosis index, which suggested that special attention should be paid to the selection of F1 hybrids in these traits in breeding. The mean values of F1 hybrids were significantly lower than those of their higher parents in all the traits but close to or significantly lower than those of their mid-parent values except for kernel length and amylose content; and significantly higher than those of their lower parents except for brown rice recovery, milled rice recovery and gel consistency.     

Comparison of Grain Quality Characteristics Between F1 Hybrids and Their Parents in Indica Hybrid Rice

Sixteen widespread elite indica parents including seven CMS lines and nine restorer lines, and their 63 F1 hybrids were chosen to compare the eleven traits of grain quality. Overall results showed that the frequency of negative over dominance, dominance and partial dominance was much higher than that of positive ones and heterosis, indicating that the values of F1 hybrids were generally lower than the means of their parents in quality characteristics. There existed apparent disparity in grain quality performance among F1 hybrids varied with the traits. The characteristics of chalky area percentage, chalky grain percentage, gel consistency and head rice recovery had a great variation in all kinds of tested heterosis indices including the mid parent heterosis index, over high value parent heterosis index and over low value parent heterosis index, which suggested that special attention should be paid to the selection of F1 hybrids in these traits in breeding. The mean values of F1 hybrids were significantly lower than those of their higher parents in all the traits but close to or significantly lower than those of their mid parent values except for kernel length and amylose content; and significantly higher than those of their lower parents except for brown rice recovery, milled rice recovery and gel consistency.     

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,     

Relationship of egg parasitoids of rice planthoppers between rice and non-rice habitats

Egg parasitoids, Anagrus spp. and Oligositaspp. have been found to be important biological agents in suppressing rice planthoppers in Asian countries. However, most of these studies have been confined to conditions within rice fields. In this study, field surveys were made to study the floral and faunal diversity in various habitats surrounding rice fields. The rice and grass (Echinochloa spp.) plants were infested with 2 gravid females of brown planthopper Toya spp. or T. pusanus per tiller respectively for two days. The oviposited plants were:1) Rice plants bearing BPH eggs, 2) grass plants bearing BPH eggs, 3) grass plants bearing Toya spp eggs, and 4) grass plants bearing T. pusanus eggs. Above plants were placed in the rice field, the grassy area adjacent to rice fields and the grassy area away from rice fields, respectively. Potted plants with host     

Prediction of the Physicochemical and Nutraceutical Characteristics of ‘Hass’ Avocado Seeds by Correlating the Physicochemical Avocado Fruit Properties According to Their Ripening State

Plant Foods for Human Nutrition - Vegetal wastes are currently a source of pollution due to the excess of organic compounds in the environment. Seeds are the main by-product of the avocado industry...     

Understanding the relationship between volunteers’ motivations and learning outcomes of Citizen Science in rice ecosystems in the Northern Philippines

This study relies on the Flying Beauties Citizen Science project conducted in the Philippines to assess personal motivations and learning outcomes of volunteers who were involved in documenting butterflies and dragonflies in rice ecosystems. While evaluation of motivations of volunteers in Citizen Science is not new, at least in affluent western countries, little is done in investigating volunteers’ motivations and learning outcomes of Citizen Science projects in low-income countries. Using surveys, we collected data from volunteers that were analysed qualitatively and quantitatively. We adopted a two stages evaluation format—before and after volunteers finished the project exercise. We compared pre-motivations to motivations attained and changes in level of knowledge before and after the project ended. We use Spearman’s Rho, Kendall’s Tau—nonparametric tests to draw correlations between variables. The results showed that key determinants that drove people to volunteer in the project were (a) learning about species and (b) being part of scientific research and the principal learning outcome was improved awareness about ecosystem functions of the species.     

【Short Report】Influence of the Improved System of Rice Intensification (SRI) on Rice Yield,Yield Components and Tillering Characteristics under Different Rice Establishment Methods

Abstract

The impacts of the system of rice intensification (SRI) and conventional management (CM) on grain yield, yield components and tillering capacity were examined under 4 rice establishment methods transplanting (TP), seedling casting (SC), mechanical transplanting (MT) and direct seeding (DS). SRI produced significantly higher grain yield than CM under TP and MT but not under DS or SC. DS and SC produced much higher seedling quality than TP or MT, suggesting that robust seedlings with vigorous roots weaken the positive effect of SRI on rice yield. SRI produced a higher tillering rate than CM, but did not affect ear-bearing tiller rate significantly. Moreover, the net photosynthetic rate of the recent fully expanded leaf at mid-tillering stage was significantly higher in SRI than in CM under MT and TP. The obtained results also indicated that SRI increased biomass accumulation before heading and improved utilization of photosynthates in the grain-filling stage.     

Relationship between rice heading sensitivity and male-sterile sensitivity to photoperiod in view of developmental genetics

We studied the relationship between the heading sensitivity and the male-sterile sensitivity in photoperiod-sensitive genic male-sterile rice (PC-MSR) and conventional rice. Materials used in this study were 7001S, a late maturing PGMS japonica strain derived from Nongken 58S; Akihikari and Youmang-zaojing(YMZJ),     

Relationship between changes of endogenous ABA level and resistance in hybrid rice under temperature stress

We studied the relationship between endogenous ABA and resistance to temperature stress in seedlings of hybrid rice. The hybrid rice Combinations Shanyou 63, Shanyou 287, Weiyou 63, and Weiyou 287 were treated under 2℃ and 42℃ respectively for 48 h. Endogenous ABA concentrations were obtained by gas chromatography with electron capture detector ( GC-ECD ) and a nickel labelled external standard. Leakage of electrolytes were determined.     

Effects of Free-air CO2 Enrichment on Root Characteristics and C：N Ratio of Rice at the Heading Stage

The CO2 concentration in Earth’s atmosphere is increasing rapidly due to human activities, like fossil fuel combustion and rapid deforestation and is predicted to reach a concentration of 550 μmol/mol within this century [1]. The increase in atmospheric CO2 has a large potential to alter many ecosystem processes, particularly C and N cycling [2-4]. Plant C:N ratio not only serves as an important factor in maintaining the quality of plant tissue, but also a key index to keep balance betwee…