Although recent and projected increases in atmospheric carbon dioxide can alter plant phenological development, these changes have not been quantified in terms of floral outcrossing rates or gene transfer. Could differential phenological development in response to rising CO2 between genetically modified crops and wild, weedy relatives increase the spread of novel genes, potentially altering evolutionary fitness? Here we show that increasing CO2 from an early 20th century concentration (300 µmol mol−1) to current (400 µmol mol−1) and projected, mid-21st century (600 µmol mol−1) values, enhanced the flow of genes from wild, weedy rice to the genetically altered, herbicide resistant, cultivated population, with outcrossing increasing from 0.22% to 0.71% from 300 to 600 µmol mol−1. The increase in outcrossing and gene transfer was associated with differential increases in plant height, as well as greater tiller and panicle production in the wild, relative to the cultivated population. In addition, increasing CO2 also resulted in a greater synchronicity in flowering times between the two populations. The observed changes reported here resulted in a subsequent increase in rice dedomestication and a greater number of weedy, herbicide-resistant hybrid progeny. Overall, these data suggest that differential phenological responses to rising atmospheric CO2 could result in enhanced flow of novel genes and greater success of feral plant species in agroecosystems. 
NEW DELHI, MAR 20: “As per the reports received from the state government, the yield of wet paddy has been recorded at 22.4 tonnes per hectare and that of dry paddy at 20.16 tonnes a hectare in the district of Nalanda, Bihar...,” Mr Pawar said in a written reply to Lok Sabha. The record yield was achieved under demonstration on System of Rice Intensification (SRI) which was organised at farmer’s field during kharif 2011, he added. “It has surpassed the yield of 19 tonnes per hectare which was recorded earlier in China,” Mr Pawar said. 
Scientists are scouring the deep and “wild” end of the rice gene pool to help find hidden traits and genes that can help breed new rice varieties better at thriving and producing food in difficult environments. Via Luigi Guarino 
The study of weed origins and evolutionary history is the poor cousin of the archaeobotany of crop domestication. Archaeobotanists can potentially do much more on this, and undoubtedly should. To provide some inspiration it is worth considering some recent insights from genetics, to do with weedy rice. While it is surely the case that rice's wild progenitors may act as weeds in the crop, it now appears that much weedy rice is descended from the crop and not directly from the wild progenitor. 
The origins of Sedentism and agriculture in early China Sedentarization and the appearance of agriculture are two of the most momentous evolutionary steps towards the emergence of complex societies in human history. These two developments, together with pottery and polished stone tools, have been generally regarded as part of Neolithization. However, recent studies from many regions in the world have shown that the beginnings of sedentariness and the emergence of food production did not always coincide. On the one hand, sedentism could be practiced in non-agricultural societies; on the other hand, the progress from low-level food production to agriculture may have taken many millennia, during which domesticates did not play an important role in subsistence strategies. In Chinese archaeological research, the origins of cereal and animal domestication have long been emphasized, but much less attention has been paid to sedentism. In this workshop we intend to investigate the evidence from interdisciplinary perspectives for understanding the initial transition from mobile hunter-gatherer lifeways to sedentism, the development and various formulations of sedentism, the emergence of plant/animal domestication, and the relationships between sedentarization and food production in China. 
Apparent amylose content (AAC) is a key determinant of eating and cooking quality in rice and it is mainly controlled by the Wx gene which encodes a granule-bound starch synthase (GBSS). In this study, sixteen single-segment substitution lines harboring the Wx gene from 16 different donors and their recipient HJX74 were used to detect the naturally occurring allelic variation at the Wx locus. The AAC in the materials varied widely and could be grouped into glutinous, low, intermediate, and two high AAC sub-classes, high I (24.36–25.20%) and high II (25.81–26.19%), under different experimental environments, which showed a positive correlation with the enzymatic activity of GBSS. One insertion/deletion (InDel) and three single nucleotide polymorphisms in the Wx gene were detected and their combinations resulted in the variation of five classes of AAC. Based on the results of AAC phenotypes, GBSS activities and cDNA sequences, five Wx alleles, wx, Wx t, Wx g1, Wx g2, and Wx g3, were identified, two of which, Wx g2 and Wx g3, are separated for the first time in this study. Under different cropping seasons, the AAC differed significantly for the Wx t and Wx g1 alleles, with higher AAC in the fall season than in the spring season, but did not differ significantly for the wx, Wx g2, and Wx g3 alleles. In conclusion, the present results might contribute to our understanding of the naturally occurring allelic variation at the Wx locus and will facilitate the improvement of rice quality by marker-assisted selection. 
Your source for information on rice and the best rice store on the internet. 
Fine mapping of the qCTS4 locus associated with seedling cold tolerance in rice (Oryza sativa L.).
Image from: http://www.chinese-black-rice.com/ 
Seed dormancy—the temporary failure of a viable seed to germinate under favorable conditions—is a complex characteristic influenced by many genes and environmental factors. To detect the genetic factors associated with seed dormancy in rice, we conducted a QTL analysis using chromosome segment substitution lines (CSSLs) derived from a cross between Nona Bokra (strong dormancy) and Koshihikari (weak dormancy). Comparison of the levels of seed dormancy of the CSSLs and their recurrent parent Koshihikari revealed that two chromosomal regions—on the short arms of chromosomes 1 and 6—were involved in the variation in seed dormancy. Further genetic analyses using an F2 population derived from crosses between the CSSLs and Koshihikari confirmed the allelic differences and the chromosomal locations of three putative QTLs: Sdr6 on chromosome 1 and Sdr9 and Sdr10 on chromosome 6. The Nona Bokra alleles of the three QTLs were associated with decreased germination rate. We discuss the physiological features of the CSSLs and speculate on the possible mechanisms of dormancy in light of the newly detected QTLs. 
The authors present new research on social and economic developments in southern China in the Early Holocene, ninth to fifth millennia BC. The ‘Neolithic package’ doesn't really work for this fascinating chapter of the human experience, where pottery, social aggregation, animal domestication and rice cultivation all arrive at different places and times. The authors define the role of the ‘pottery-using foragers’, sophisticated hunter-gatherers who left shell or fish middens in caves and dunes. These colonising non-farmers shared numerous cultural attributes with rice cultivators on the Yangtze, their parallel contemporaries over more than 5000 years. Some agriculturalists became hunter-foragers in turn when they expanded onto less fertile soils. No simple linear transition then, but the practice of ingenious strategies, adaptations and links in a big varied land 
A small group of farmers in Bangladesh were secretly and sacredly nurturing in field the unique rice variety (or species!) that has two (sometime three) grains in a rice seed. Via Luigi Guarino 
For centuries, traditional agricultural systems have contributed to food and livelihood security throughout the world. Recognizing the ecological legacy in the traditional agricultural systems may help us develop novel sustainable agriculture. We examine how rice–fish coculture (RF), which has been designated a “globally important agricultural heritage system,” has been maintained for over 1,200 y in south China. A field survey demonstrated that although rice yield and rice-yield stability are similar in RF and rice monoculture (RM), RF requires 68% less pesticide and 24% less chemical fertilizer than RM. A field experiment confirmed this result. We documented that a mutually beneficial relationship between rice and fish develops in RF: Fish reduce rice pests and rice favors fish by moderating the water environment. This positive relationship between rice and fish reduces the need for pesticides in RF. Our results also indicate a complementary use of nitrogen (N) between rice and fish in RF, resulting in low N fertilizer application and low N release into the environment. These findings provide unique insights into how positive interactions and complementary use of resource between species generate emergent ecosystem properties and how modern agricultural systems might be improved by exploiting synergies between species. 
Cold tolerance at the seedling stage of rice is an important phenotypic trait that causes normal plant growth and stable rice production in temperate regions as well as tropical high-lands in Asia and Africa. In order to find quantitative trait loci (QTLs)/genes associated with cold tolerance, we constructed a linkage map using 153 recombinant inbred lines (RILs) derived from a cross between a cold-tolerant temperate japonica cultivar, Geumobyeo, and a cold-sensitive tropical japonica breeding line, IR66160-121-4-4-2. The RILs were phenotyped for cold tolerance or sensitivity based on the degrees of cold tolerance as cold tolerance indices at the seedling stage. The seedlings for cold-tolerance/-sensitive traits were scored on the 7th day of the recovery period at 25°C after cold treatment at 10°C. Two QTLs (qCTS4a and qCTS4b) associated with cold tolerance at the seedling stage were identified on the long and short arms of chromosome 4 with an LOD score of 2.89 and 2.75, respectively, using composite interval mapping. The QTLs were flanked by simple sequence repeat (SSR) markers RM3648-RM2799 and RM3375a-RM558 that explained 8.3 and 7.8% of the total phenotypic variation, respectively. Seven of the selected RILs expressed cold tolerance at both the seedling and reproductive stages. The SSR markers associated with the QTLs will be useful for tracking favorable QTLs/genes into cold-sensitive elite cultivars and may have potential for pyramiding different QTLs for the improvement of cold tolerance in rice. |
As part of the GCP-040 project, farmers near the village of Kamangu, Katanga province, in the Democratic Republic of Congo have received improved-variety seeds, tools, and technical training to increase the yield of their crops. 
The system of rice intensification (SRI) is gaining ground across Asia as more and more governments come to rely on it for food security. 
ScienceDirect.com - Palaeoworld -Abstract 
Weedy rice has been becoming a notorious weed in the paddy field of China in recent decades due to its increasing damage to rice yield and rice quality. In this study, a microsatellite technique with 21 pairs of SSR markers was utilized to estimate the genetic structure of two biotypes of weedy rice with Japonica and Indica rice characteristics, collected from Liaoning and Guangdong provinces, respectively. The genetic diversity of the weedy rice in the two provinces was relatively low (Liaoning h = 0.086; Guangdong h = 0.160), and distinctly large genetic differences existed between these two provinces (Gcs = 0.623). The genetic diversity was found primarily within populations, and genetic differentiation was relatively low within the same province. Both cluster analysis (UPGMA) and principle component analysis (PCA) showed that weedy rice had a closer relationship with the cultivated rice collected from the sample field than with other cultivated rice and common wild rice varieties in China. Thus, the results of this study on samples from the Liaoning and Guangdong provinces in China support the de-domestication hypothesis that weedy rice most probably originated from local cultivated rice. 
Seed size is an important trait in determinant of rice seed quality and yield. In this study, we report a novel semi-dominant mutant S mall and r ound s eed 5 (Srs5) that encodes alpha-tubulin protein. Lemma cell length was reduced in Srs5 compared with that of the wild-type. Mutants defective in the G-protein alpha subunit (d1-1) and brassinosteroid receptor, BRI1 (d61-2) also exhibited short seed phenotypes, the former due to impaired cell numbers and the latter due to impaired cell length. Seeds of the double mutant of Srs5 and d61-2 were smaller than those of Srs5 or d61-2. Furthermore, SRS5 and BRI1 genes were highly expressed in Srs5 and d61-2 mutants. These data indicate that SRS5 independently regulates cell elongation of the brassinosteroid signal transduction pathway 
Heading date in rice is an important agronomic trait controlled by several genes. In this study, flowering time of variety Dianjingyou 1 (DJY1) was earlier than a near-isogenic line (named NIL) carried chromosome segment from African rice on chromosome 3S, when grown in both long-day (LD) and short-day (SD) conditions. By analyzing a large F2 population from NIL × DJY1, the locus DTH3 (QTL for days to heading on chromosome 3) controlling early heading date in DJY1 was fine mapped to a 64-kb segment which contained only one annotated gene, a MIKC-type MADS-box protein. We detected a 6-bp deletion and a single base substitution in the C-domain by sequencing DTH3 in DJY1 compared with dth3 in NIL, and overexpression of DTH3 caused early flowering in callus. Quantitative real-time PCR revealed that the transcript level of dth3 in NIL was lower than that DTH3 in DJY1 in both LD and SD conditions. The Early heading date 1 (Ehd1) which promotes the RFT1, was up-regulated by DTH3 in both LD and SD conditions. Based on Indel and dCAPs marker analysis, the dth3 allele was only present in African rice accessions. A phylogenetic analysis based on microsatellite genotyping suggested that African rice had a close genetic relationship to O. rufipogon and O. latifolia, and was similar to japonica cultivars. DTH3 affected flowering time and had no significant effect on the main agronomic traits. 
Forbidden black rice could be next superfood - Black rice, regularly used in China but uncommon in the West, could be one of the healthiest foods, say experts. 
Five months after lifting a ban on exports of cheaper varieties of rice, India has emerged as one of the world's top rice exporters. Via Luigi Guarino It is generally understood that foxtail millet and broomcorn millet were initially domesticated in Northern China where they eventually became the dominant plant food crops. The rarity of older archaeological sites and archaeobotanical work in the region, however, renders both the origins of these plants and their processes of domestication poorly understood. Here we present ancient starch grain assemblages recovered from cultural deposits, including carbonized residues adhering to an early pottery sherd as well as grinding stone tools excavated from the sites of Nanzhuangtou (11.5–11.0 cal kyBP) and Donghulin (11.0–9.5 cal kyBP) in the North China Plain. Our data extend the record of millet use in China by nearly 1,000 y, and the record of foxtail millet in the region by at least two millennia. The patterning of starch residues within the samples allow for the formulation of the hypothesis that foxtail millets were cultivated for an extended period of two millennia, during which this crop plant appears to have been undergoing domestication. Future research in the region will help clarify the processes in place. 
What it is to have friends, especially knowledgeable friends. Bhuwon Sthapit, local rice wallah extraordinaire,1 responded quickly and in depth when asked what he knew about triple-grained rice. Via Luigi Guarino The development of the environmentally conserving dike-pond system of integrated agriculture and aquaculture in the Zhujiang Delta of south China is traced to illustrate the impact of environmental changes on technological innovations. The technologies of dike building, land reclamation, pond fish culture, and crop cultivation on dikes, which were either independently developed or modified from ideas brought in by migrant farmers from northern China, represented farmers' efforts to adapt to the new characteristics of a changed environment as population pressure increased. The new technologies revealed the farmers' awareness of the need for environmental conservation. However, increased population pressure also necessitated more intensive use of the land, both in the highland and lowland regions, giving rise to inappropriate dike building and premature reclamation activities, which in turn brought about more frequent flooding in the delta region. Careless application of a new technology tended to have harmful effects on the environment. Political conditions in different periods of China's economic development have also caused changes in the dike-pond system which has to maintain high productivity and profitability. Recent advances in dike-pond system technology have focused on crop diversification and animal husbandry to match the three-dimensional characteristics of its ecological components. New agricultural technologies can be successful in China only if they can provide a balance between land use and conservation. |
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