Comparative Performance of Hybrid and Elite Inbred Rice Varieties with respect to Their Source‐Sink Relationship

Abstract

Hybrid rice varieties have higher yield potential over inbred varieties. This improvement is not always translated to the grain yield and its physiological causes are still unclear. In order to clarify it, two field experiments were conducted including two popular indica hybrids (BRRI hybrid dhan2 and Heera2) and one elite inbred (BRRI dhan45) rice varieties. Leaf area index, chlorophyll status, and photosynthetic rate of flag leaf, postheading crop growth rate, shoot reserve translocation, source-sink relation and yield, and its attributes of each variety were comprehensively analyzed. Both hybrid varieties outyielded the inbred. However, the hybrids and inbred varieties exhibited statistically identical yield in late planting. Both hybrids accumulated higher amount of biomass before heading and exhibited greater remobilization of assimilates to the grain in early plantings compared to the inbred variety. Filled grain (%) declined significantly at delayed planting in the hybrids compared to elite inbred due to increased temperature impaired-inefficient transport of assimilates. Flag leaf photosynthesis parameters were higher in the hybrid varieties than those of the inbred variety. Results suggest that greater remobilization of shoot reserves to the grain rendered higher yield of hybrid rice varieties.

Integration of chemical and manual control methods for sustainable weed management in inbred and hybrid rice

“…found from a study that hybrid rice produced higher spikelets panicle -1 than inbred rice varieties. Similar type of results was also found from a study conducted by Haque et al (2015). They found that hybrids exhibited significantly lower number of panicles m -2 and on average 33.95% higher number of spikelets panicle -1 compared to the tested inbred.…”

E Efficacy and Economics of Herbicidal Weed Management in Monsoon Rice of Bangladesh

“…Currently, it is believed that high yielding inbred varieties developed through conventional breeding have reached in yield plateau. Hybrid rice cultivars have a 15-30% yield advantage over modern inbred rice varieties, therefore, hybrid rice technology is considered as the key approach for increasing global rice production (Walker et al, 2008;Chauhan et al, 2011;Haque et al, 2015). It is also reported that even in weedy conditions, the yield of hybrid cultivars is high .…”

Pre-Planting Hardening-Induced Variability in Yield Attributes and Yield of Inbreed and Hybrid Rice

“…Grain yield of rice depends on the source-sink relationship (Zhao et al, 2006). Hybrid varieties have efficient capacity to supply assimilates to the grain from the source and the capacity of the sink to receive it fixes the higher yield than the inbred varieties (Haque et al, 2015). The number of unfilled grain increased in BRRI hybriddhan4 than the two inbred varieties.…”

“…Hybrid rice varieties have more photosynthesis capacity because of containing higher amount of chlorophyll in their leaf (Tang et al, 2010). In addition, flag leaf of hybrid rice contained more chlorophyll than the inbred rice genotypes which contributed to increase the photosynthesis capacity during panicle initiation (Haque et al, 2015). Higher photosynthesis potentiality of hybrid varieties attributed to accumulate higher amount of dry matter.…”

“…Researcher indicated that pollen sterility increased in hybrid varieties over 33ºC (Chakrabarti et al, 2010). In the other hand, relatively high temperature impaired slow rate of translocation of assimilated from source to sink ultimately causes higher unfilled grain in hybrid rice than inbred (Haque et al, 2015).…”