Nine genotypes were evaluated under greenhouse conditions for antixenosis and tolerance against brown planthopper （BPH, Nilaparvata lugens Stal）. In antixenosis studies, proportion of insects settled on a test genot...Nine genotypes were evaluated under greenhouse conditions for antixenosis and tolerance against brown planthopper （BPH, Nilaparvata lugens Stal）. In antixenosis studies, proportion of insects settled on a test genotype in relation to the susceptible control TN1 was recorded, with significantly lower proportion of nymphs （55.22%-59.18%）, adult males （60.33%-60.75%）, and adult females （80.56%- 79.26%） settled on RP2068-18-3-5 and Ptb33 in relation to those on TN1. Based on number of feeding sites, the test genotypes were ranked in order from the highest to the lowest as RP2068-18-3-5, Ptb33, MR1523, Rathu Heenati, Sinnasivappu, ARC10550, MO1, INRC3021 and TNI. The order was exactly reverse in terms of fecundity expressed as number of eggs laid per female. In tolerance studies, days to wilt, functional plant loss index and plant dry weight loss to BPH dry weight produced were recorded. RP2068-18-3-5, Rathu Heenati and Ptb33 performed better than the other test genotypes. These results helped in relative quantification of BPH resistance levels in the genotypes. RP2068-18-3-5, a new effective source of BPH resistance, can be used in resistance breeding after tagging of resistant genes/QTLs linked to different parameters of antixenosis and tolerance with selectable molecular markers.展开更多
Most of the aromatic rice cultivars are susceptible to disease, insect-pest attack and are more prone to lodging. Therefore, nitrogen is the key input for increasing the productivity of aromatic rice. Research analyzi...Most of the aromatic rice cultivars are susceptible to disease, insect-pest attack and are more prone to lodging. Therefore, nitrogen is the key input for increasing the productivity of aromatic rice. Research analyzing the effects of N level on yield and quality characteristics of modem aromatic cultivars in the north-western Indo-Gangetic Plains is not well documented. Therefore, the present study was conducted to optimise the N levels for higher yield and better quality of the modem aromatic rice cultivars. The mean grain yield increased by 22.5% when plots were supplemented with 40 kg/ha of N application as compared to control （unfertilized）. Among cultivars, Punjab Mehak 1 registered highest yield （5.3 t/ha） followed by Pusa Basmati 1121 （4.78 t/ha） and Punjab Basmati 2 （4.66 t/ha） respectively. Interactive effect between N levels and cultivars on grain yield revealed that in Punjab Mehak l, grain yield responded significantly up to 60 kg/ha of N application as compared to Pusa Basmati 1121 and Punjab Basmati 2 where it responded only upto 40 kg/ha of N application. All the quality characteristic found to be improved with N application, whereas amylose content decreased with 60 kg/ha of N application as compared to 20 and 40 kg/ha of N application.展开更多
Insufficient N supply is an important constraint to productivity of lowland rice. Studies on N nutrition of rice cultivars with different durations representing the north western part of Indo-Gangetic Plains are scant...Insufficient N supply is an important constraint to productivity of lowland rice. Studies on N nutrition of rice cultivars with different durations representing the north western part of Indo-Gangetic Plains are scanty. A field experiment was conducted during kharif seasons of 2006 and 2007 at PAU, Ludhiana to assess the differences in grain yield and N utilization of three popular rice cultivars at varying N doses. Significant differences among genotypes were observed in grain yield, N uptake, N use efficiency and N utilization efficiency. The cultivar PAU-201 was found to be superior among all the tested genotypes. Total N uptake and grain N uptake was highest in cultivar PAU-201 followed by cultivars PR-115 and PR-113. On an average, the response to applied N for grain yield was observed upto 90 kg N ha1. Grain yield increased significantly up to 90 kg N hal in cultivars PR-115 and PAU-201 and up to 120 kg N ha1 in PR-113. Apparent recovery efficiency （ARE） and Partial factor productivity （PFPN） of N was significantly reduced at higher level of N （150 kg N hal）. It was concluded that N uptake is predominant factor in grain yield formation and cultivars differ in NUE suggesting that it may be possible to develop cultivars that are efficient at low nutrient level or are capable of using N more efficiently when applied as fertilizer.展开更多
文摘Nine genotypes were evaluated under greenhouse conditions for antixenosis and tolerance against brown planthopper （BPH, Nilaparvata lugens Stal）. In antixenosis studies, proportion of insects settled on a test genotype in relation to the susceptible control TN1 was recorded, with significantly lower proportion of nymphs （55.22%-59.18%）, adult males （60.33%-60.75%）, and adult females （80.56%- 79.26%） settled on RP2068-18-3-5 and Ptb33 in relation to those on TN1. Based on number of feeding sites, the test genotypes were ranked in order from the highest to the lowest as RP2068-18-3-5, Ptb33, MR1523, Rathu Heenati, Sinnasivappu, ARC10550, MO1, INRC3021 and TNI. The order was exactly reverse in terms of fecundity expressed as number of eggs laid per female. In tolerance studies, days to wilt, functional plant loss index and plant dry weight loss to BPH dry weight produced were recorded. RP2068-18-3-5, Rathu Heenati and Ptb33 performed better than the other test genotypes. These results helped in relative quantification of BPH resistance levels in the genotypes. RP2068-18-3-5, a new effective source of BPH resistance, can be used in resistance breeding after tagging of resistant genes/QTLs linked to different parameters of antixenosis and tolerance with selectable molecular markers.
文摘Most of the aromatic rice cultivars are susceptible to disease, insect-pest attack and are more prone to lodging. Therefore, nitrogen is the key input for increasing the productivity of aromatic rice. Research analyzing the effects of N level on yield and quality characteristics of modem aromatic cultivars in the north-western Indo-Gangetic Plains is not well documented. Therefore, the present study was conducted to optimise the N levels for higher yield and better quality of the modem aromatic rice cultivars. The mean grain yield increased by 22.5% when plots were supplemented with 40 kg/ha of N application as compared to control （unfertilized）. Among cultivars, Punjab Mehak 1 registered highest yield （5.3 t/ha） followed by Pusa Basmati 1121 （4.78 t/ha） and Punjab Basmati 2 （4.66 t/ha） respectively. Interactive effect between N levels and cultivars on grain yield revealed that in Punjab Mehak l, grain yield responded significantly up to 60 kg/ha of N application as compared to Pusa Basmati 1121 and Punjab Basmati 2 where it responded only upto 40 kg/ha of N application. All the quality characteristic found to be improved with N application, whereas amylose content decreased with 60 kg/ha of N application as compared to 20 and 40 kg/ha of N application.
文摘Insufficient N supply is an important constraint to productivity of lowland rice. Studies on N nutrition of rice cultivars with different durations representing the north western part of Indo-Gangetic Plains are scanty. A field experiment was conducted during kharif seasons of 2006 and 2007 at PAU, Ludhiana to assess the differences in grain yield and N utilization of three popular rice cultivars at varying N doses. Significant differences among genotypes were observed in grain yield, N uptake, N use efficiency and N utilization efficiency. The cultivar PAU-201 was found to be superior among all the tested genotypes. Total N uptake and grain N uptake was highest in cultivar PAU-201 followed by cultivars PR-115 and PR-113. On an average, the response to applied N for grain yield was observed upto 90 kg N ha1. Grain yield increased significantly up to 90 kg N hal in cultivars PR-115 and PAU-201 and up to 120 kg N ha1 in PR-113. Apparent recovery efficiency （ARE） and Partial factor productivity （PFPN） of N was significantly reduced at higher level of N （150 kg N hal）. It was concluded that N uptake is predominant factor in grain yield formation and cultivars differ in NUE suggesting that it may be possible to develop cultivars that are efficient at low nutrient level or are capable of using N more efficiently when applied as fertilizer.
