**5. Sikkim primitive maize variety**

The economy of North-eastern India relies primarily on rice cultivation; however, in Sikkim, maize is the dominant crop. This underscores the crop's significance, although there has been a recent shift toward more profitable crops. Maize originated in Mexico, but India harbors considerable genetic diversity. The maize landraces in Sikkim can be classified into four groups based on their historical origin: primitive, advanced or derived, recent introductions, and hybrid races. The primitive group

**Figure 8.**

*(a) Sikkim Primitive 1, Murali makai grown in Dzongu (photo courtesy: Dawa Lhendup Lepcha) and (b) Tempo Rinzing, Lachung, North Sikkim (photo courtesy: Hishey Lachungpa).*

*Exploring the Diversity of Maize (*Zea mays *L.) in the Khangchendzonga Landscapes… DOI: http://dx.doi.org/10.5772/intechopen.112566*

**Figure 9.** *Murali makai (a) Tinvong, Dzong North Sikkim, and (b) Amba, East Sikkim.*

comprises several races of popcorn, including *Poorvi Botapa*, *Tirap Nag-Sahypung*, *Arun Tepi*, and *Alok Sapa*, which are distributed in the Eastern Himalayas, including Sikkim, at elevations ranging from 600 to 2000 m. The most primitive race, *Poorvi Botapa*, exists in pure form in North Sikkim, where it is known as *murali makai*. Two forms of *murali makai* are present, with different kernel colors (purple and yellow kernel maize), and designated as Sikkim Primitive-1 (purple kernel type) and Sikkim Primitive-2 (yellow kernel type). Notable varietal characteristics of *murali makai* include its prolific ear-bearing ability (with 3–5 cobs per plant, a rare trait in commercial maize), the presence of style remnants on the mature kernel, small cob size (8 cm long and 6 cm girth), and approximately 100 small kernels per cob. Despite the small kernel size, the popping efficiency is high, with a 100 kernel weight of 9.5 g (**Figures 10** and **11**).

Sikkim Primitive maize strains, namely Sikkim Primitive-1 (purple colored), and Sikkim Primitive-2 (yellow colored), were found to differ from the primitive Mexican races [5, 10]. Some of the local varieties, such as *Seti* and *Pahenli*, exhibit a thick husk coverage and an oblong cob orientation, which provide resistance against ear rot during the rainy season. Extra-earliness, a rare trait in mid and high-altitude maize, is observed in the high-altitude maize variety called *Tempo Ringing*, which reaches maturity in 85–90 days in mid-hills, outpacing other maize cultivars in silking completion. Fascinating local germplasm with promising traits, such as *Murli*, *Tempo Ringing*, and *Seti*, are currently being utilized in an ongoing breeding program at the ICAR, Sikkim Centre, Tadong (**Figure 12**) [22].

#### **Figure 10.**

*Sikkim Primitive 1, grown in Dzongu, North Sikkim; Sikkim Primitive 2, grown in Dzongu, North Sikkim.*

**Figure 11.** *Murali makai (Sikkim Primitive 2) grown in Sikkim.*

### **5.1 Sikkim Primitive: a distinct maize landrace**

In a study conducted by Sharma et al. [23], a diverse set of 48 maize landraces/locals sourced from various agroecologies across India were selected for analysis. Among these, 8 accessions were identified as "Sikkim Primitives", which were collected from

*Exploring the Diversity of Maize (*Zea mays *L.) in the Khangchendzonga Landscapes… DOI: http://dx.doi.org/10.5772/intechopen.112566*

**Figure 12.** *Tempo rinzing maize variety of Lachung, North Sikkim (photo courtesy: Hishey Lachungpa).*

different villages in Sikkim in November 2005. The remaining 40 accessions comprised 21 landraces from Northeastern Hill (NEH) regions (excluding Sikkim Primitives), 4 from non-NEH tribal hill regions, and 15 from the plains of India. This diverse set of landraces provided an opportunity to understand the genetic and phenotypic diversity present in maize germplasm in India. This study aimed to characterize maize landraces in India using both intensive phenotypic and molecular analyses. Through multilocation analyses of selected accessions, the study identified several promising landrace accessions that could be potentially useful in breeding programs. The utilization of SSR markers analyzed through DNA Sequencer technology by Sharma et al. [23] enabled an effective differentiation of accessions. Additionally, the Sikkim Primitives landrace accessions were found to be distinct at both the phenotypic and molecular levels when compared to other landrace accessions in India. These findings highlight the importance of conducting detailed characterization of germplasm collections to fully exploit their genetic potential.
