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28 June 2005, Volume 12 Issue 2 Previous Issue    Next Issue
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Research Paper

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Relationship Between Blast Resistance Phenotypes and Resistance Gene Analogue Profiles in Rice LIU Er-ming , XIAO Yi-long , YI You-jin , ZHUANG Jie-yun , ZHENG Kang-le , LOU Feng 2005, 12(2): 75-82 .  Abstract ( )   PDF (69KB) ( )   A total of 21 rice varieties were assayed based on RGA-PCR using six pairs of RGA primers and evaluated for leaf blast resistance in the nursery as well. Cluster analysis showed that the varieties could be classified into five groups either at the similarity threshold of 0.72 for RGA profiles or at 0.80 for leaf blast severities. Although there did not exist a complete parallel relationship between RGA-based groups and blast resistance-based groups, five out of six varieties with broad spectrum or durable resistance repeatedly fell into same group. This result suggested that application of three primer pairs, viz. RGA1 and RGA2 (both designed from the LRR region of rice Xa21 gene) and RGA3 (designed from the LRR region of tobacco N gene) contributed to better evaluation of the germplasms for their resistance responses to rice blast.

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Endosperm Development in Autotetraploid Rice WANG Lan, LIU Xiang-dong, LU Yong-gen, FENG Jiu-huan, XU Xue-bin, XU Shi-xiong (S. Y. Zee) 2005, 12(2): 83-91 .  Abstract ( )   PDF (448KB) ( )   By using the laser scanning confocal microscope and plastic (Leica 7022 historesin embedding kit) semi-thin sectioning technique, comparative studies on the development of endosperm were carried out between autotetraploid and diploid rices. About one third of the ovaries in the autotetraploid showed normal endosperm development as those in the diploid. In these ovaries, one of the polar nuclei would fuse with the sperm nucleus, and the primary endosperm nucleus formed and underwent the first division in 4 hours after pollination; the anticlinal wall began to grow centripetally between the free nuclei starting from the wall ingrowths of the embryo sac near the micropylar end, and some of the phragmoplasts formed transformed into periclinal walls. In addition, some of the cell wall situated in the middle of the endosperm appeared to originate from phragmoplasts, whereas others seemed to develop randomly without the obvious formation of phragmoplasts. Cellulose began to accumulate in the wall of aleurone cell layer at 6 days after pollination. The cellulose wall of the cells of the aleurone cell layer appeared to have completely formed within 7 to 8 days after pollination. On the other hand, about two thirds of the ovaries in the autotetraploid showed abnormality in endosperm development with various types, such as non-fertilization, abnormal fertilization, endosperm development-delay and non-synchronization in the development of cellulose wall of cells of the aleurone layer. These abnormalities usually resulted in decreased seed setting in autotetraploid rice.

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Plant Ideotype at Heading for Super High-Yielding Rice in Double-Cropping System in South China CHEN You-ding , WAN Bang-hui , ZHANG Xu 2005, 12(2): 92-100 .  Abstract ( )   PDF (54KB) ( )   The newly released super high-yielding hybrid rice combinations, Yueza 122, Fengyou 428, Peiza 67, and the super high-yielding conventional cultivars, Guangchao 3 and Shengtai 1, were grown in both early and late seasons. The morphological characters of each population were investigated at the heading stage, and the data were analyzed by using ANOVY and other statistic methods. The plant ideal morphological characters at the heading stage were established as follows: 1) for the early-season cropping, 90–105 cm plant height; 11–12 tillers per plant; 35–40 cm length and 2.1–2.2 cm width of flag leaf; 46–50 cm length and 1.8–2.1 cm width of the second leaf from the top (L2); 59–64 cm length and 1.4–1.9 cm width of the third leaf from the top (L3); 7°–14°, 18° and 20°–33° for the ideal leaf angles of the flag leaf, L2 and L3, respectively; 2) for the late-season cropping, 90–100 cm plant height; 9–15 tillers per plant; 30–41 cm length and 1.8–2.0 cm width of flag leaf; 53–61 cm length and 1.3–1.8 cm width of L2; 52–58 cm length and 1.2–1.5 cm width of L3; 9°–19°, 15°–37° and 16°–49° for the ideal leaf angles of the flag leaf, L2 and L3, respectively. The main physiological characteristics of these varieties were also analyzed.

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Correlation of Plant Morphological and Grain Quality Traits with Mineral Element Contents in Yunnan Rice ZENG Ya-wen, SHEN Shi-quan, WANG Lu-xiang, LIU Jia-fu, PU Xiao-ying, DU Juan, QIU Min 2005, 12(2): 101-106 .  Abstract ( )   PDF (39KB) ( )   Correlations between four grain quality, 24 plant morphological traits and eight element contents of 653 accessions from Yunnan rice were analyzed. P, K, Ca and Mg contents of core collection were closely correlated to the most plant morphological and grain quality traits, and there were highly significant correlations (P <0.01) among some traits including P content to number of stems and tillers, K content and amylose content, Ca content and plant height, Mg content and protein content. Mn, Zn, Cu and Fe contents of core collection were closely related to a few traits, such as Fe content and gel consistency (-0.1121**), Zn content and seed setting rate (-0.1411**), Cu content and number of grains per panicle (-0.1398**), Mn content and plant height (-0.2492**).

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Effects of Uniconazole on Nitrogen Metabolism and Grain Protein Content of Rice XIANG Zu-fen, YANG Wen-yu, REN Wan-jun, WANG Xiao-chun 2005, 12(2): 107-113 .  Abstract ( )   PDF (54KB) ( )   The effects of uniconazole by soaking seeds and spraying leaves at booting stage with different concentrations (0, 20 and 40 mg/kg) on the nitrogen metabolism of flag leaf and grains after flowering, and rice grain protein content and yield were studied with hybrid rice combination Shanyou 63. Under uniconazole treatment, the soluble protein content in flag leaf was increased in early and middle period of grain filling, but this content was nearly the same as or even lower than that of control at maturity; Glutamine synthetase activity in superior and inferior grains and non-protein nitrogen content in superior grains at early stage of grain development were promoted, and moreover, the transforming speed from non-protein nitrogen to protein nitrogen was accelerated; Non-protein nitrogen content was lower than that of control at maturity, but protein nitrogen content at each stage was higher than those of control; Protein nitrogen content in superior and inferior grains and protein nitrogen absolutely accumulative content in a grain both were enhanced and protein content and yield in rice grain were raised. The application of uniconazole by soaking seeds and spraying leaves raised crude protein content by an average of 7.2% and 8.3%, and protein yield by an average of 13.1% and 13.4%, respectively.

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Effects of Polyamines Synthesis Inhibitors Sprayed after Heading on Contents and Components of Polyamines in Rice Grains at the Ripening Stage JI Xiao-jia , YU Bing-jun , ZHANG Da-dong , LIU You-liang 2005, 12(2): 114-118 .  Abstract ( )   PDF (35KB) ( )   With a higher polyamine rice (indica variety Jinlingxiang) as experimental material, the changes in contents and components of polyamines (PAs) in rice grains after harvesting were investigated under the treatments by spraying the panicles and flag leaves of rice with PAs synthesis inhibitors, D-Arg (0.5, 1.0, 1.5 and 2.0 mmol/L), methylglyoxal bis-guanylhydrazone (MGBG) (0.1, 0.5, 1.0 and 1.5 mmol/L) and cyclohexylamine (CHA) (1.0, 5.0, 10.0, 15.0 and 20.0 mmol/L), at the heading, flowering and grain filling stages. The inhibition of D-Arg on the contents of free and bound PAs and its total amounts in rice grains was significant, especially treated at the flowering and grain filling stages. Treatments with MGBG and CHA affected mainly the components of PAs, and their effects on the total amounts of PAs were not significant except MGBG at the flowering stage and CHA at both heading and flowering stages.

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Effect of Supplied P Levels on Rice Growth and Uptake of P and Zn in Different P-Efficiency Genotypes GUO Zai-hua, HE Li-yuan, XU Cai-guo 2005, 12(2): 119-124 .  Abstract ( )   PDF (59KB) ( )   A soil pot culture experiment with four supplied P levels (i.e. P30, P50, P100, P200, representing supplemental P 30, 50, 100, 200 mg/kg, respectively) was conducted to investigate uptake and use ability to P and Zn in the rice genotypes with different P-efficiency, of which rice genotypes 508, 99011, 580, 99112 were low-P tolerant and 99056, 99012 were low-P sensitive. Low-P tolerant rice 580 and 99011 absorbed more P than the others, and rice genotype 580 had stronger uptake ability especially at low-P level such as P50 and P30. 508 could absorb considerable P, and had the lowest P percentage of shoot, indicating it had good performance in P-use efficiency. These three rice genotypes had larger biomass and less response to changed P level than rice genotype 99112, 99056 and 99012. Rice genotype 99112 showed Low-P tolerance mainly by sacrificing biomass to maintain high relative grain yield. The least amount of P absorbed by 99056 showed it had the lowest P uptake efficiency, and the highest P percentage in shoot of 99012 meant it had the lowest P use efficiency. So they two showed low-P sensitivity. Zn contents in shoot under P200, P100 and P50 were similar, but P30 increased Zn content in shoot significantly. The Zn contents in shoot of 99112, 99056 and 99012 were higher than those of 508, 99011 and 580, especially at tillering stage and booting stage. As for total Zn content in shoot, Low-P tolerant rice genotype 580 had the largest amount and followed by 99011 and 508, low-P tolerant rice genotype 99012 had the smallest amount at the three sampling stage and followed by 99056. Furthermore, P/Zn in shoot of 99012 was the highest, and that of 99056 was the smallest at the same P level.

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Effects of Soil Copper Concentration on Growth, Development and Yield Formation of Rice (Oryza sativa) XU Jia-kuan, YANG Lian-xin, WANG Zi-qiang, DONG Gui-chun, HUANG Jian-ye, WANG Yu-long 2005, 12(2): 125-132 .  Abstract ( )   PDF (65KB) ( )   Pot experiments were conducted in 2002 and 2003 to investigate the effects of soil copper(Cu) concentration on growth, development and yield formation of rice by using the japonica cultivar Wuxiangjing 14 and hybrid rice combination Shanyou 63. The plant height, leaf number, elongated internode number and heading date of rice plants were not affected at soil Cu levels below 200 mg/kg, but affected significantly at above 400 mg/kg. The inhibitory effects on rice growth and development were increased with the increment of soil Cu levels. The grain yields decreased significantly with raising soil Cu levels. The main reasons for the grain yield reductions under lower soil Cu levels (100, 200 mg/kg) were mainly due to the decrease of number of spikelets per panicle, however, under higher soil Cu levels (more than 400 mg/kg), both panicle number and number of spikelets per panicle contributed to the yield loss. The decreases of panicle number by Cu stress were mainly attributed to slow recovery from transplanting, delayed tillering and reduced maximum tiller numbers. The reduction of number of spikelets per panicle under soil Cu stress resulted from the decreases of both shoot dry weight (SDW) at the heading date and the ratio of spikelets to SDW. Total biomass at maturity decreased significantly with the increase of soil Cu levels, while economic coefficient showed non-significant decrease except under soil Cu levels above 800 mg/kg.

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Resistance Performance to Whitebacked Planthopper in Different Phenotypes of Japonica / Indica Doubled Haploid Rice Lines Kazushige SOGAWA , HU Jiang , ZENG Long-jun , QIAN Qian , ZENG Da-li 2005, 12(2): 133-136 .  Abstract ( )   PDF (35KB) ( )   Field performance of whitebacked planthopper (WBPH)-resistance of four phenotypes was evaluated in Chunjiang 06 (CJ-06) / TN1 DH rice lines, which were expressed by different combinations of sucking inhibitory and ovicidal traits inherited independently from CJ-06. WBPH established the highest populations in susceptible DH lines that had neither sucking inhibitory- nor ovicidal resistance. Both immigration and subsequent population levels were kept below the damage-causing density in the sucking inhibitory DH lines even under a WBPH outbreak. WBPH could not build up populations in the DH lines having both the sucking inhibitory and ovicidal resistance. Although WBPH immigrated preferentially to non-sucking inhibitory DH lines with ovicidal resistance, subsequent population buildup was significantly suppressed. It was concluded that the differential performance to WBPH-resistance in CJ-06 / TN1 DH lines was primarily due to the sucking inhibitory trait, and complementarily to the ovicidal trait.

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Review and Prospect on Japonica Hybrid Rice Research in Anhui Province, China LI Cheng-quan, WANG Shou-hai, WANG De-zheng, LUO Yan-chang, ZHANG Pei-jiang, WU Shuang, DU Shi-yun, XU Chuan-wan 2005, 12(2): 137-144 .  Abstract ( )   PDF (53KB) ( )   The breeding history and commercial exploitation of japonica hybrid rice in Anhui Province, China over the last three decades were reviewed. Besides, the bottleneck problems restricting the development of japonica hybrid rice in China were summarized, and corresponding technological countermeasures were proposed.

Experimental Technique

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Rapid Determination of Silicon Content in Rice Dai Wei-min, Zhang Ke-qin, Duan Bin-wu, Sun Cheng-xiao, Zheng Kang-le, Cai Run, Zhuang Jie-yun 2005, 12(2): 145-147 .  Abstract ( )   PDF (52KB) ( )   A method for rapid determination of silicon content in rice was introduced. The reliability of this method was verified by using a recombinant inbred line (RIL) population of rice cross Zhenshan 97B / Milyang 46. Two hundred and forty-nine RILs were transplanted in two replications. Simple correlation coefficients on the silicon content in the hull, flag leaf and stem in rice between duplicate samples of 498 rice materials were 0.97954, 0.97026 and 0.98848, respectively. Ten representative samples were selected for measurement using the high-temperature alkaline fusion method. Simple correlation coefficient between the silicon contents determined by the high-temperature alkaline fusion method and by the present method is 0.9993.

Short Communication

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Physiological Macro-lesions Enhanced Resistance to Blast (Magnaporthe grisea) in Rice Near-isogenic Lines HUANG Shi-wen, LU Ji-ying, LUO Kun, ZHANG Xiu-fu, QIAN Qian 2005, 12(2): 148-150 .  Abstract ( )   PDF (31KB) ( )   Roll-leaf-1 (rl-1) and spot-leaf-1 (spl-1) were two near-isogenic lines, which were obtained after 3 to 4 backcrosses with early season indica rice Zhefu 802 as recurrent parent. Henna macro-lesions, referred as physiological or morphological markers, began to appear on leaves at 4.5- to 6.0-leaf stage. The rice seedlings were inoculated at 3.5-, 5.0- and 7.0-leaf stages with high pathogenic races Zhong A1 and Zhong B1 of Magnaporthe grisea, respectively. The resistance of rl-1, spl-1 and Zhefu 802 against blast was significantly different. The seedlings of Zhefu 802 at 3.5- to 7.0-leaf stage were susceptible to races Zhong A1 and Zhong B1 of M. grisea, whereas those of rl-1 and spl-1 at 3.5-, 5.0- and 7.0-leaf stages were susceptible, moderately resistant and resistant, respectively. These results suggested that the enhanced resistance of rl-1 and spl-1 related to the appearance of their morphological marker lesions. The experiment provided a basis for studying lesion mimic and hypersensitive response in association with disease resistance.