Anthesis silking interval a difference of the average number of days between the maize tassel flowering and the first visible silk (stigma) on the maize ear. Abstract : when maize (zea mays l) is stressed at flowering because of deficits of water, light, nutrients, and sometimes by long photoperiods and lack of thermal adaptation, ear growth slows in relation to tassel growth and the anthesis-silking interval (asi) increases. Results to elucidate the genetic control of drought in maize, we evaluated approximately 5000 inbred lines from 30 linkage-association joint mapping populations under two contrasting water regimes for seven drought-related traits, including yield and anthesis-silking interval (asi. Experiments conducted by cimmyt demonstrated that maize varieties such as katumani composite escape drought and have a long anthesis to silking interval (asi) asi which is defined as the duration between male and female flowering in maize, has been used successfully to select drought tolerant maize.
Minimum anthesis-silking interval (25) was observed for hp1100-24, and hp1100-14, while maximum anthesis-silking interval (60) was observed for hp1097-5 lsd for comparison among the means was 164 ( table 2 . Grain yield as a function of mean anthesis-silking interval (asi), ears plant i weight kernel- 1 and kernels ear- 1 for 50 progeny trials (166-250 s 1 or 4 6 - 1 6 0 $2, 3 progenies each across two replicates) from six tropical maize populations under a range of water regimes at tlaltizapfin, m6xico, 1986-1990. In maize, a major effect of water stress is a delay in silking, resulting in an increase in the anthesis-silking interval, which is an important cause of yield failures diverse strategies are used by breeding programs to improve drought tolerance.
Abstract when maize (zea mays l) is stressed at flowering because of deficits of water, light, nutrients, and sometimes by long photoperiods and lack of thermal adaptation, ear growth slows in relation to tassel growth and the anthesis-silking interval (asi) increases. Summary of the 68 meta qtl (mqtl) for grain yield and anthesis-silking interval detected across 18 maize populations the number of mqtl identified on each chromosome varied from 4 on chromosome 10 to 9 on chromosome 1, with an average of 68 mqtl per chromosome. Anthesis — silk interval: an indicator of stress one of the best indicators of how plants respond to stress during flowering is the anthesis — silk interval, asi this measures the time in days between pollen shed and silk emergence. The narrow asi is (anthesis-silking interval) very useful trait to increase kernel numbers in maize genotype(s) (bolanos and edmeades, 1996 ribaut et al, 1996) in addition to other morpho-physiological traits.
Meta-analyses of qtl for grain yield and anthesis silking interval in 18 maize populations evaluated under water-stressed and well-watered environments kassa semagn 1 email author , yoseph beyene 1 . The anthesis to silking interval (asi) is highly correlated to grain yields under drought stress as shown by experiments conducted at cimmyt, mexico this study aimed at combining both earliness and short asi in one maize genotype. Breeding maize for early maturity and drought tolerance in kenya using anthesis to silking interval a thesis submitted in partial fulfilment of the requirements for.
Anthesis-silking interval of 30 days was recorded for the hybrids p1x x p5, p3 x p5 and p5 x p12 whereas p1 x p3 (05) had the lowest value of anthesis-silking interval (table 1. Elevated temperature showed no significant effects on duration or peak dates of silking and anthesis, and thus on anthesis-silking interval grain yield tended to decrease with temperature elevation above ambient, showing a sharper linear decrease with mean growing season temperature increase in junda 6 than in chalok 1. Anthesis-silking interval (asi) under drought has become shorter in modern hybrids, and selection has possibly led to an increase in the growth of spikelets and ears and a reduction in final spikelet number (bänziger et al, 2000. Under combined stresses, which shortened the anthesis-silking period and interval (asi) that caused more kernel setting than suwan 4452), pioneer 30b80 failed to complete 100% silking under pbd silking was more affected than anthesis by both stresses especially under pbd.
From -3814% for anthesis-silking interval to 9980% for plant heightthe highest grain yield of 1857 and 1810 (t/ha) were obtained from limu and jabi in that order. The data were sub- 86 kahiu ngugi et al: anthesis to silking interval usefulness in developing drought tolerant maize jected to anova using genstat-5 computer program those genotypes which flowered at less than 57 days from the means were separated using lsd. Maize, the most important stable crop in kenya is affected by drought stress mostly at flowering stages causing delay in silk emergence the anthesis to silking interval (asi) is highly correlated.
Maize (zea mays l) is one of the most important crops 1980), and elongation of the anthesis-silking interval (wooley et al, 1962 bassetti and westgate, 1994. The capacity to predict time to silking relative to anthesis in maize (zea mays l) has important implications for breeding and seed production we developed a theoretical quantitative framework for simulating the anthesis to silking interval (asi) based on plant growth and biomass partitioning to the ear. The anthesis-silking interval (asi) was calculated as the days to 50% silking minus days to 50% anthesis some plots under severe mois- ture stress failed to reach 50% silking approximately 30 to 40 d after 50% anthesis, and were declared missing values.