Easy and rapid detection of iron in rice grain

In this study, we show how a preliminary determination of grain Fe in rice may be made with reaction to Perls’ Prussian blue, a stain for Fe (III). Differential localization of Fe in grain parts was indicated by the intensity of reaction of tissue Fe to the dye. The blue colour reaction was most intense in the embryo, weak in the aleurone layer of the pericarp and invisible in the endosperm. The staining intensity also varied with the region of the embryo, generally being strongest in the scutellum, intermediate in the coleorhiza and weakest in the coleoptile. Variation in the reaction to Perls’ Prussian blue was observed among eleven rice genotypes with varying grain Fe contents. The intensity of the blue colour reaction in the embryo of different rice genotypes was indicative of their grain Fe contents for both brown and white (polished) rice. Those with high grain Fe, >14 mg Fe kg-1, were clearly distinguishable from those with <10 mg Fe kg-1 with Perls’ Prussian blue. We suggest that this simple staining procedure may be used to quickly screen for high Fe contents in large germplasms containing hundreds of rice entries, using reactions in genotypes with known grain contents as standards

Variation of milling and grain physical quality of dry season Pathum Thani 1 in Thailand

Pathum Thani 1 (PTT1) is a photoperiod-insensitive, aromatic Thai rice variety that is grown year-round. The rice from some locations is often priced lower than others due to sub-standard grain quality. This study sought to determine the limiting grain quality characteristic(s) in dry season PTT1 and their distribution across Thailand’s irrigated rice regions. To do so, we evaluated the milling and physical quality of milled rice grain of dry season PTT1 from 24 provinces in 5 regions in Thailand. Sixty-seven paddy rice samples were collected and evaluated for head rice yield, chalkiness, whiteness, and translucency. Head rice yield varied by region, with the highest (48.1%) found in samples from the Central region, compared to 34.5-39.7% elsewhere. Head rice chalkiness was the physical quality that varied more widely among the provinces within each region than among regions, with chalkiness at a level that would adversely affect price in more than one-half of the samples. Contrary to the general perception that chalky grain is less resistant in milling, head rice yield actually increased with total chalkiness, expressed as % chalky grain by weight. The total chalkiness correlated negatively with translucency, while the head rice chalkiness correlated positively with whiteness. Grain chalkiness was identified as the grain quality attribute of PTT1 rice that varied with location; this directly affected the price of milled rice grain, as well as indirectly through its relationship with head rice yield and visual appearance of the milled rice grai

Responses of milling quality to nitrogen and water management in modern long grain rice varieties

This study determined how nitrogen (N) fertilizer and water management affect grain yield and milling quality of 9 modern rice varieties with long, slender grain in two field experiments. The effect of N on rice grown in wetland culture was evaluated at 0, 60 and 120 kg N ha-1. In a second experiment the rice in aerobic and wetland culture were compared. The rice in both experiments were grown to maturity and evaluated for yield, head rice yield and chalkiness. Grain yield increased with increasing N application, head rice yield increased with increasing N in 8 varieties, while chalkiness was more than halved in 7 varieties. Grain N also increased with increasing N fertilizer, but high head rice yield in several varieties was associated with relatively low grain N. Under aerobic cultivation, all 9 varieties yielded less than in wetland culture, the head rice yield was lower and chalkiness was higher except in 2 varieties. In both experiments, grain yield was associated positively with head rice yield and negatively with chalkiness. Head rice yield and chalkiness were negatively associated in the water experiment but not in the N experiment. This study has shown that modern high yielding rice varieties generally respond positively to nitrogen fertilizer in better milling quality as well as in yield. Grain chalkiness of the varieties was more stable against variation in the environment than head rice yield

Effects of arbuscular mycorrhizal fungi on a fallow enriching tree (Macaranga denticulata)

Macaranga denticulata is a fallow enriching species that is important in upland agriculture in parts of northern Thailand. The root zone of this tree supports a high biodiversity of arbuscular mycorrhizal (AM) fungi and it has been postulated that these are important for Macaranga to rapidly establish in disturbed fields. To evaluate this, seedlings were inoculated with spores of AM fungi (Glomus spp., G. fasciculatum, Acaulospora spp. and mixed species of AM fungi) collected from the field, and then grown without P fertilizer. Growth of the host was compared with plants grown concurrently at six rates of phosphorus application (0 to 150 mg P/kg soil). The experiments were conducted in pots containing 5 kg sterilized soil. Arbuscular mycorrhizal inoculation increased height and plant dry weight. Dry weights of M. denticulata inoculated with Acaulospora spp. or mixed species of AM fungi were equivalent to uninoculated plants given 150 mg P/kg soil, whereas plants inoculated with Glomus spp and G. fasciculatum were similar to those with 25 mg P/kg soil. Nutrient contents of plant inoculated with Acaulospora spp. and mixed species of AM fungi were higher than plants inoculated with Glomus spp and G. fasciculatum. Root colonization of plants inoculated with Acaulospora spp. and mixed species of AM fungi was not significantly different, and was higher than other inoculated treatments. These experiments have shown that M. denticulata is dependent on AM fungi for rapid growth in a low P soil. Acaulospora morrowiae appeared to be the dominant species sporulating in root zones of plants inoculated with either Acaulospora spp. or mixed species of AM fungi. Further work is required to identify the most effective AM species for M denticulata since the abundance of AM spores in the root zone may not be directly related to the effectiveness of root colonization in nutrient uptake of the tree

Nitrogen transfer from forage legumes to nine neighbouring plants in a multi-species grassland

Legumes play a crucial role in nitrogen supply to grass-legume mixtures for ruminant fodder. To quantify N transfer from legumes to neighbouring plants in multi-species grasslands we established a grass-legume-herb mixture on a loamy-sandy site in Denmark. White clover (Trifolium repens L.), red clover (Trifolium pratense L.) and lucerne (Medicago sativa L.) were leaf-labelled with 15N enriched urea during one growing season. N transfer to grasses (Lolium perenne L. and xfestulolium), white clover, red clover, lucerne, birdsfoot trefoil (Lotus corniculatus L.), chicory (Cichorium intybus L.), plantain (Plantago lanceolata L.), salad burnet (Sanguisorba minor L.)and caraway (Carum carvi L.) was assessed. Neighbouring plants contained greater amounts of N derived from white clover (4.8 gm-2) compared with red clover (2.2 gm-2) and lucerne (1.1 gm-2). Grasses having fibrous roots received greater amounts of N from legumes than dicotyledonous plants which generally have taproots. Slurry application mainly increased N transfer from legumes to grasses. During the growing season the three legumes transferred approximately 40 kg N ha-1 to neighbouring plants. Below-ground N transfer from legumes to neighbouring plants differed among nitrogen donors and nitrogen receivers and may depend on root characteristics and regrowth strategies of plant species in the multi-species grassland

Nitrogen balance and root behavior in four pigeonpea-based intercropping systems

A medium-duration pigeonpea (Cajanus cajan L. Millsp.) is usually grown as intercrop. A wide range of crop combination in pigeonpea-based intercropping systems is found in India and eastern Africa (Ofroi and Stern, 1987; Rao and Willey, 1980; Venkateswarlu and Subramanian, 1990). Although much information is available on the production efficiency and monetary advantage of intercropping, very little is known about the nitrogen (N) economy and root behavior. The study was carried out to examine how the nitrogen balance sheet and root development of pigeonpea could be altered by companion crops

Medicinal Plant Use and Health Sovereignty: Findings from the Tajik and Afghan Pamirs

Medicinal plants are indicators of indigenous knowledge in the context of political volatility and sociocultural and ecological change in the Pamir Mountains of Afghanistan and Tajikistan. Medicinal plants are the primary health care option in this region of Central Asia. The main objective of this paper is to demonstrate that medicinal plants contribute to health security and sovereignty in a time of instability. We illustrate the nutritional as well as medicinal significance of plants in the daily lives of villagers. Based on over a decade and half of research related to resilience and livelihood security, we present plant uses in the context of mountain communities. Villagers identified over 58 cultivated and noncultivated plants and described 310 distinct uses within 63 categories of treatment and prevention. Presence of knowledge about medicinal plants is directly connected to their use