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18 November 1987, Volume 1 Issue 3 Previous Issue    Next Issue
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研究报告
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研究报告

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The Influence of Photoperiod on the Fertility Changes of Hubei Photo-sensitive Genic Male-sterile Rice (HPGMR) Zhang Ziguo,Yuan Shengchao,Xu Chuanzhen 1987, 1(3): 137-143 .  Abstract ( )   PDF (1329KB) ( )   The critical-day length inducing the fertility changes of late keng Nong-Ken 58(A-B) and E-Yi 105(A-B) was 13.75-14.00 hours during secondary rachis-branch and spikelet primordia to pollen mother cell formation stage, sterile pollens would be induced by day-length above 14.00 hours. If the long dark period was interrupted by light intensity above 50 lx for l hour or 200 lx for 15 minutes, the sterile plants were also induced as treated under long-day condition. It was thus clear that actually the long dark period determined the pollen fertility of HPGMR. The critical dark period would be 10.00-10.15 hours, the critical light intensity which determined fertility of HPGMR was 5-50 lx, the effects of intensity below 5 lx similar to dark-period and above 50 lx as long-day photo-period. Light period above 50 lx before sunrise and after sunset might be the cause of the difference between artificial light and natural sunshine for inducing fertility changes in HPGMR. These results would be used as a basis to forecast the suitable region and seasons for producing hybrid and self seeds using HPGMR.

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The Throry and Method of Rice Breeding for Ideal Plant Morphology: Part II. Varietal difference in leaf quality in relation to yield components Zhang Longbu,Chen Wenfu,Yang Shouren 1987, 1(3): 144-154 .  Abstract ( )   PDF (1766KB) ( )   Rice breeding for ideal plant morphology is in effect the breeding for high light utilization. Thus, its theoretical basis is inevitably to both the genetic and physiological aspects of knowledge. The varietal difference in specific leaf weight and chlorophyll content, which are regarded as the essential elements of leaf quality, is quite significant, especially the former seems to be more stable than the latter and more consistent under different conditions. Besides, there is significant positive correlation between specific leaf weight and chlorophyll content, each of them is positively correlated with leaf nitrogen content to be highly significant, and the latter in turn is positively correlated with net photosynthetic rate to be highly significant too. Leaf area, specific leaf weight and chlorophyll content are highly related to well-filled grains per panicle and to the average panicle weight, with the order leaf area > specific leaf weight > chlorophyll content in the degree of relationship. Among these, the direct effect of specific leaf weight in relation to panicle weight is comparatively more marked, and that of chlorophyll content may become more and more important with respect to dry matter production in the later stage of growth. Therefore, in rice breeding for ideal plant morphology, in particular for maximal sunlight utilization, while leaf area is to be firstly considered, attention should also be paid to specific leaf weight and chlorophyll content. Since estimation of leaf area, specific leaf weight and chlorophyll content is rather easy to handle, which can be done either by eye (for leaf area and chlorophyll content) or by hand touching, this method is of practical importance in screening so large progeny as in rice breeding.

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Genetic Effects of Cytoplasm on Agronomic Characteristics in Hybrid Rice (in English) Sheng Xiaobang 1987, 1(3): 155-170 .  Abstract ( )   PDF (2825KB) ( )   Studies were conducted on the effects of eight male sterile cytoplasms, WA, Liu-Ye, Shen-Qi, Gambiaka(G-type), Hong-Ye, BT, Dian I and Dian 3, on twelve agronomic characteristics in hybrid rice. Peroxidase isozyme analysis was made on the mature anthers of some combinations and their parents. Results showed that there were negative effects of the eight sterile cytoplasms on plant height, panicle exsertion, number of panicles per plant, percentage of effective panicles, number of filled grains per panicle, setting percentage, 1000-grain weight, grain weight per plant, with differences among different combinations; heading date was apparently delayed. The cytoplasmic effects showed the same tendency in the zymograms of the peroxidase isozymes. Comparing the results of our experiments with those reported in literature, we suggest that the phenotypic effects of made sterile cytoplasm on hybrid rice are genetic phenomena closely related to sterility. But as for the yields, the negative effects of male sterile cytoplasm do not change the direction and degree of the heterosis of combinations with high combining ability and high restorability. In the paper, a formula was first introduced for evaluating cytoplasmic effect in heterosis.

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Study of Uplifting the Culture Capacity of Mature Rice Seed Zhao Chengzhang 1987, 1(3): 171-176 .  Abstract ( )   PDF (1013KB) ( )   The experimental results indicated that the mature rice seed is a competitive explant. Since the reaction of ABA on scutellum is not sensitive and higher level of ABA can inhibit the plumule and radicle, so that it promotes the scutellum callus growth. The callus were compact, white and very uniform. The adjustment of medium concentration enhanced effectively the frequency of plant regeneration and reduced the frequency of the dead callus. Higher level of 2,4-D (> 1 mg/l) and BA (1 mg/l) are harmful to callus formation and regeneration in mature seed culture of indica rice. The reaction of indica rice variety on 2,4-D, BA was more sensitive than japonica rice variety. Adding 2,4-D 0.5 mg/l, BA 0.5 mg/l and ABA 5 mg/l to MS inducing medium for mature seed culture is suitable.

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The Bacteriophage Technique for Estimating Xanthomonas campestris pv. oryzae in Leaf Tissues (in English) Zhang Qi,T W Mew 1987, 1(3): 177-183 .  Abstract ( )   PDF (987KB) ( )   The bacteriophage technique was tested to enumerate the bacterial multiplication in leaf tissues of rice. In the absence of a selective medium, the method proved to be efficient and reliable to establish the bacterial number in leaves of different positions of Zenith after infection. A good correlation between phage count and viable count (direct isolation) by the dilution plating was also demonstrated.

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Deep Placement of N-fertilizer (Urea) Topdressed to Unsaturated Paddy Soil with Reflooded Water Chen Rongye,Zhang Jiancai,Guo Wangmo,Chen Wei 1987, 1(3): 184-191 .  Abstract ( )   PDF (1310KB) ( )   The paper offers a very simple, practical and efficient technique for deep placement of urea topdressed in irrigated rice fields. The technique combines N fertilizer application method with soil moisture regime control. The specific way to use the technique is that urea as N fertilizer was topdressed on rice fields, where moisture regime had become unsaturated by cutting off the water supply and draining, then irrigation should be immediately done after application of urea to make the fertilizer deep placement in reduced zone with downward infiltrating water. The results obtained in the study, which consists of soil column experiment, pot experiment and field experiment, show that fertilizer nitrogen efficiency can be substantially increased with the technique, which resulted in more than 60% of topdressed urea deep-placed in reduced zone and minimized its N-losses. As compared the technique with conventional broadcasting N fertilizer on flooded rice field, 1.5 kg N/mu (22.5 kg N/ha) can be saved to get the comparable high yield (around 7.4 t /ha) and significantly higher yield can be obtained at an equal N level of 7.5 kg/mu.

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Milled Rice Qualities in Hong Kong Market Luo Yukun,Min Jie,Wu Xujun 1987, 1(3): 192-197 .  Abstract ( )   PDF (1031KB) ( )   The appearances and cooking and eating qualities of milled rice of 11 indica varieties in Hong Kong market were studied. The data on grain physicochemical properties showed that a very high appearance quality of milled rice with the small amount of chalkiness, good translucency and long slender grain were demanded. The mean amylose content, gel consistency and gelatinization temperature, which are major indices of cooking and eating qualities, fell in the category of low-medium (about 20%), soft and low (55-69℃) respectively. A significant coefficient between panel taste scores and prices in Hong Kong market indicated that a soft texture of cooked rice might be preferred not only by the Hong Kong people, but also by a large numbers of the domestic people. A Comparison of rice grain qualities of some inland indica varieties with those in the Hong Kong market from other countries was made, and some differences were revealed.

研究简报

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Studies on the Screening of Resistant Rice Cultivars to Pyricularia oryzae and Xanthomonas campestris pv. oryzae Zhang Xuebo,Xia Yihou,Xu Wenyao,Lin Chenghui 1987, 1(3): 198-200 .  Abstract ( )   PDF (544KB) ( )