Heterosis in yield, fiber quality, and photosynthesis of okra leaf oriented hybrid cotton (Gossypium hirsutum L.)

Abstract

Leaf shape is an important factor affecting canopy structure, photosynthetic characteristics, and yield. Introducing okra leaf shape is considered an important strategy in cotton heterosis breeding. The objective of the study was to evaluate the heterosis in okra leaf cotton hybrid F 1 s, which were developed by crossing two sterile near isolines and three restorer near isolines. A normal leaf check hybrid F 1 , Zhongza 29, and four newly developed okra leaf oriented hybrid F 1 s, including the superokra (severely cleft and narrowly lobed leaf), okra (deeply cleft and narrowly lobed leaf), semi-okra (intermediate leaf lobe), and sub-okra (large leaf lobe) hybrids were selected in this experiment. Okra leaf oriented cotton hybrids significantly reduced leaf area index (LAI) (P \ 0.0001), thus more light penetrated into the lower canopy. The LAIs for the super-okra and okra hybrids, however, were too small to supply adequate photosynthate, thus resulting in early maturity, short boll filling period, and low yield. As the LAI increases, the semi-okra and sub-okra hybrids showed certain heterosis. The semi-okra hybrid showed 7-12% heterosis over the check hybrid in lint percent, 6-11% in boll weight, 2-147% in canopy light intensity, 1-10% in net photosynthetic rate (Pn), and -3 to 3% in lint yield. As well, all tested okra leaf hybrids improved fiber quality such as micronaire compared with the normal leaf check hybrid. The results suggested that adopting okra leaf parental lines in cotton breeding provided potentials in increasing fiber quality with comparable lint yield.

Modulation of morphological and biochemical traits using heterosis breeding in coloured cotton

“…Heterosis breeding is an effective tool to enhance the yield and enrich quality parameters (Srivastava 2000;Dutt et al 2004;Li 2005) and availability of CMS and restorer factors facilitated the production of cotton hybrids at commercial scale (Wang et al 2004;Zhang et al 2007). Useful heterosis has more practical implications as it conveys a more straightforward message to plant breeders and farmers, compared to mid-parent and best parent heterosis (Hua et al 1963;Dong et al 2007;Zhu et al 2008;Geddam et al 2011). In the present study, the performance of interspecific coloured cotton hybrids regarding yield was significantly higher than intraspecific hybrids, thus demonstrating the commercial potential of interspecific hybrids (Dutt et al 2004;Zhao & Wang 2005; Kantartzi & Roupakias 2010).…”

“…The modern concept of heterosis (hybrid vigour) in crops was defined by Shull in 1908 (Randhawa & Singh 1994). Since then, many plant breeders have documented intraspecific and interspecific heterosis in cotton (Wang et al 2004;Wu et al 2004;Dong et al 2006Dong et al , 2007Zhu et al 2008; Kantartzi & Roupakias 2010;Geddam et al 2011) and found that interspecific crosses displayed more heterosis than intraspecific heterosis, thus having more commercial potential (Baloch et al 1993;Zhang et al 2007). The availability of cytoplasmic male sterility (CMS) and fertility restorer parents has facilitated highyield hybrid seed production throughout the world (Wang et al 2004;Zhang et al 2007;Zhu et al 2008).…”

“…Since then, many plant breeders have documented intraspecific and interspecific heterosis in cotton (Wang et al 2004;Wu et al 2004;Dong et al 2006Dong et al , 2007Zhu et al 2008; Kantartzi & Roupakias 2010;Geddam et al 2011) and found that interspecific crosses displayed more heterosis than intraspecific heterosis, thus having more commercial potential (Baloch et al 1993;Zhang et al 2007). The availability of cytoplasmic male sterility (CMS) and fertility restorer parents has facilitated highyield hybrid seed production throughout the world (Wang et al 2004;Zhang et al 2007;Zhu et al 2008). Heterosis in white-fibred cotton has been extensively studied, both physiologically and genetically (Hao et al 2008;Tokatlidis et al 2008Tokatlidis et al , 2011Gerardeaux et al 2009); however, naturally coloured cotton has not been so well studied.…”

iTRAQ-facilitated proteomic profiling of anthers from a photosensitive male sterile mutant and wild-type cotton (Gossypium hirsutum L.)

“…The F 1 progeny of cotton performs strong heterosis in boll number, boll weight, and seed cotton yield. The hybrid seeds are widely produced in India and China [1]. However, the current cotton hybrid seeds are mainly produced through hand emasculation and pollination, which requires a large labor force and cost.…”

Selection and Characterization of a Novel Photoperiod‐Sensitive Male Sterile Line in Upland Cotton

“…Upland cotton ( Gossypium hirsutum L.) is one of the world's most important economic crops, producing mostly textile fiber and the second‐most valuable oil (Yin et al ). It has strong heterosis in boll number, boll weight, and seed cotton yield (Zhu et al ). The hybrid seeds are widely planted and propagated in India and China (Yin et al ).…”