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Adhikari NR, Ghimire SK, Sah SK, Koirala KB.2015. Flowering, reproductive behaviors and their effects on grain yields of newly bred single cross hybrids of yellow maize (Zea mays L.) in winter in subtropical Nepalese Himalayan foot plain. PeerJ PrePrints3:e897v2https://doi.org/10.7287/peerj.preprints.897v2
Introduction: All the plants of a maize population or hybrid PP (plant population) do not dehisce anthers and do not emerge silk simultaneously. Generally, male flowering or anther dehiscence (anthesis) is leading and female flowering (silk emergence or silking) is lagging under both conducive and stressful environment. Enough and timely pollen availability is indispensible when silks come out of maize ears for largest number of kernel set. So, study of flowering and reproductive behavior of newly bred maize hybrids are indispensible to confirm high grain yielding hybrid with trait of simultaneous anthesis and silking (synchrony). Materials and methods: Flowering and reproductive behaviors of fifteen newly bred single cross hybrids of yellow maize have been examined in winter growing them in an RCBD trial planting their seeds on October 3, 2012 in subtropical foot plain of Himalaya. For flowering (FB); emergence of male organ (emergence of tassel or tasseling or TSS) from apical node of the stem, anthesis, silking, browning of silk or withering of silk (silk senescence or S SEN), tassel-anthesis interval (TAI), anthesis-silking interval (ASI), silking-silk senescence interval (S INI-S SEN Interval) of the hybrids have been examined dissecting the plant population (PP) into four equal parts (percent) as the first earliest, second earliest, third earliest and terminal 25% of the PP denominated as 25, 50, 75 and 100% respectively of the each of the fifteen hybrids. So, whether third earliest 25% and terminal 25% silk emerging PP denominated as SILK 75 and SILK 100% respectively will get enough pollen from the PP of the same hybrid can be determined through ASI 75 and ASI 100 of the hybrid PP. Results and discussion: A polynomial grain yield estimating regression equation (t ha-1) Y = - 11922 + 507.3*(TSS25) - 7.183*(TSS25)2 + 0.03387*(TSS25)3 with r2 value 66% has been discovered from days taken for TSS25 (TSS of earliest 25% PP). Similarly, high r2 bearing polynomial equations were from days for anthesis and silking of the PPs of the fifteen hybrids. Equations with the lowest r2 were for the days required for the silk senescence (S SEN). Reason of low r2 is that the observation of silk browning or withering could not be precise for naked eye since the silks looked fresh longer in high humidity, low temperature and cloudy day in the winter although it lost receptivity earlier. In addition, Interval duration from S INI to S SEN cannot be the duration of silk receptivity in the winter of subtropical Nepalese Himalayan foot plain. For reproductive behavior; number of functional egg cells that became successful zygotes to pull assimilates for complete kernel development can reflect aroma about reproductive strength (RS) of the hybrid. Accordingly, hybrids 8 and 5 have been found of the highest RS.
This is an updated version of the prior version.
Floral traits of single cross hybrids of yellow maize in winter in subtropical Nepalese Himalayan foot plain