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201.
The applicability of ovule culture was examined in reciprocal crosses between the diploid species D. grandiflorum L. and the tetraploid cultivar D. hybridum ‘Galahad’. An interspecific hybrid plant of D. hybridum ‘Galahad’ × D. grandiflorum was obtained,and hybridity was confirmed by chromosome counting. The hybrid was different from the parents in flower color
and size but intermediate between the parents in leaf shape. The hybrid showed low pollen fertility and failed to produce
viable seeds by either self- or backcross-pollination using fertile pollen grains from its parents. The applicability and
efficiency of the ovule culture technique for genetic improvement of the genus Delphinium through interspecific hybridization between different ploidies is discussed.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
202.
The melon (Cucumis melo) plant introduction PI 414723 was observed to segregate for resistance after inoculation with a highly
virulent non-aphid-transmissible strain of zucchini yellow mosaic potyvirus (ZYMV-NAT). By self-pollination of selected resistant
plants, the percentage of resistant plants increased in successive generations until nearly 100% in the S7 progeny. A reciprocal cross was made between a resistant S5 plant of PI 414723 and a plant of the susceptible cultivar Dulce. Parental-, filial-, and backcross- generation plants were
inoculated with ZYMV-NAT. One-half of the F1 plants, regardless of the direction of the cross, were resistant, indicating that the PI 414723 individual used for crossing
was heterozygous. The F2 generation obtained by self-pollination of resistant F1 plants segregated to resistant and susceptible in accordance with a 27:37 ratio, indicating that, in this cross, three complementary
dominant genes are needed for resistance to be expressed. The resistance to ZYMV carried by PI 414723 is oligogenic with the
number of genes observed to segregate in crossing depending on the genotype of the susceptible parent.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
203.
The wide prevalence of gluten-related disorders has led to increase in the demand for gluten-free foods. Rice is a gluten-free and less allergenic cereal. However, bread made from rice flour, i.e., gluten-free rice bread, is generally of poor quality because rice flour cannot develop a network with gluten-like properties. In this study, we investigated the effects of protease treatment on gluten-free rice to improve the quality of its bread. Bread treated with a commercial protease from Bacillus stearothermophilus (thermoase) was of higher quality, i.e., good crumb appearance, high volume, and soft texture, depending on the amount of enzyme added. Rice proteins in the protease-treated bread were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, which showed that glutelins and prolamins were hardly digested by thermoase in comparison with other proteins. Scanning electron microscopy revealed that many cellular structures were formed in the thermoase-treated bread; however, these structures were rare in the untreated control. Bread crumb color was not affected by the treatment. The staling rate was much lower for the thermoase-treated bread than for the control. These results indicate that thermoase treatment can be successfully used to improve the quality of gluten-free rice bread by partial digestion of rice proteins. 相似文献
204.
Akinori Yamamoto Hiroko Akiyama Takuji Naokawa Yasuhiro Miyazaki Yusuke Honda Yukimasa Sano Yasuhiro Nakajima Kazuyuki Yagi 《Biology and Fertility of Soils》2014,50(1):53-62
Lime-N (calcium cyanamide, CaCN2) acts as both fertilizer and pesticide. Lime-N may reduce nitrous oxide (N2O) emission from soil, although its effectiveness and the relative mechanisms are not well understood. The aim of the study was to quantify the effect of lime-N on N2O emission from the acidic soil of tea fields. The study design consisted of two treatments: conventional fertilizer (CF) (application of conventional organo-chemical fertilizer) and lime-N (LN) (application of approximately 53 % of the applied N as lime-N and the remaining as conventional organo-chemical fertilizer). Both treatments had the same amount of N, P2O5, and K2O applied to soil between plant canopies; fertilizer was incorporated into soil. We measured N2O emissions and environmental and microbial parameters of soil between plant canopies and under the canopy of tea plants, including the concentrations of dicyandiamide and cyanamide derived from lime-N. Nitrous oxide emission from soil between plant canopies was lower in the LN treatment than in the CF treatment, and soil ammonium oxidation activity and soil denitrification rate decreased after lime-N application. We applied the acetylene inhibition technique and analyzed isotopomer ratios of N2O; the results of both techniques suggested that denitrification was the major process of N2O production in the soil between plant canopies, despite relatively low water-filled pore space. Cumulative N2O emission over the 366 days of the experiment was 36.0 % lower in the LN treatment than in the CF treatment (P?<?0.05). Our results suggest that lime-N application decreases N2O emission by inhibiting both nitrification and denitrification processes in the acidic soil. 相似文献
205.
Lack of exposed ice inside lunar south pole Shackleton Crater 总被引:2,自引:0,他引:2
Haruyama J Ohtake M Matsunaga T Morota T Honda C Yokota Y Pieters CM Hara S Hioki K Saiki K Miyamoto H Iwasaki A Abe M Ogawa Y Takeda H Shirao M Yamaji A Josset JL 《Science (New York, N.Y.)》2008,322(5903):938-939
The inside of Shackleton Crater at the lunar south pole is permanently shadowed; it has been inferred to hold water-ice deposits. The Terrain Camera (TC), a 10-meter-resolution stereo camera onboard the Selenological and Engineering Explorer (SELENE) spacecraft, succeeded in imaging the inside of the crater, which was faintly lit by sunlight scattered from the upper inner wall near the rim. The estimated temperature of the crater floor, based on the crater shape model derived from the TC data, is less than approximately 90 kelvin, cold enough to hold water-ice. However, at the TC's spatial resolution, the derived albedo indicates that exposed relatively pure water-ice deposits are not on the crater floor. Water-ice may be disseminated and mixed with soil over a small percentage of the area or may not exist at all. 相似文献
206.
Buesseler KO Lamborg CH Boyd PW Lam PJ Trull TW Bidigare RR Bishop JK Casciotti KL Dehairs F Elskens M Honda M Karl DM Siegel DA Silver MW Steinberg DK Valdes J Van Mooy B Wilson S 《Science (New York, N.Y.)》2007,316(5824):567-570
The oceanic biological pump drives sequestration of carbon dioxide in the deep sea via sinking particles. Rapid biological consumption and remineralization of carbon in the "twilight zone" (depths between the euphotic zone and 1000 meters) reduce the efficiency of sequestration. By using neutrally buoyant sediment traps to sample this chronically understudied realm, we measured a transfer efficiency of sinking particulate organic carbon between 150 and 500 meters of 20 and 50% at two contrasting sites. This large variability in transfer efficiency is poorly represented in biogeochemical models. If applied globally, this is equivalent to a difference in carbon sequestration of more than 3 petagrams of carbon per year. 相似文献
207.
Yasuzumi?FujimoriEmail author Kenji?Chiba Tatsuki?Oshima Kazushi?Miyashita Satoshi?Honda 《Fisheries Science》2005,71(4):738-747
ABSTRACT: Variations in trawl dimension, bottom contact, and catch with differing warp lengths during walleye pollock surveys conducted by the Fisheries Research Agency were examined. The ratio of warp length to fishing depth (scope ratio) was set at 2.5, 3.0 and 3.5 at depths of 110 m. At a 2.5 scope ratio, the net mouth shape and footgear contact fluctuated, as the trawl door did not contact the bottom. Footgear contact was complete when the scope ratio was 3.0 or more. Walleye pollock, sculpins and flatfishes were the main catch in all tows, and the catch increased with scope ratio. There was no difference in the length frequency of walleye pollock ( n = 300) captured at 2.5 and 3.0 scope ratio. However, the length frequency at 3.5 was significantly different from that of other scope ratios. These results suggest that at a scope ratio of 3.0 or more, the trawl door will not leave the bottom at any depths. To compliment echo surveys for walleye pollock, a 3.0 scope ratio would be optimal, since the catch data for a 3.5 scope ratio was dissimilar from that of scope ratios. 相似文献
208.
Automated acoustic method for counting and sizing farmed fish during transfer using DIDSON 总被引:1,自引:0,他引:1
Counting and sizing large farmed fish such as tuna is often performed during their transfer from one net cage to another.
Dual-frequency identification sonar (DIDSON) provides an automated fish counting and sizing tool. However, its counter and
sizer are not suitable for measuring farmed fish because of net movements due to currents and subsequent frequent image breakups.
This paper presents a fully automated acoustic method to count and size farmed fish during fish transfer by using DIDSON imaging.
The background is subtracted from the image after being stabilized by an image phase-only correlation method. The segmentation
of the fish is obtained by tracing the edges with a contour tracing method. To prevent recounting the same fish, a Kalman
filter algorithm was designed and adapted to predict fish movements. Automated counting was performed by analyzing the spatiotemporal
trajectory of the track. The separated fish images were searched for and body length was obtained by summing down the centerline
segments from the head to the tail of the fish. The proposed system was verified using farmed yellowtail, Seriola quinqueradiata (mean total length 83.1 cm) to obtain a sizing error of mean total length within 2.4 cm. 相似文献